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: /proc/thread-self/root/opt/hc_python/lib/python3.8/site-packages/sqlalchemy/sql/ Upload File: files >> //proc/thread-self/root/opt/hc_python/lib/python3.8/site-packages/sqlalchemy/sql/elements.py # sql/elements.py # Copyright (C) 2005-2024 the SQLAlchemy authors and contributors # <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php # mypy: allow-untyped-defs, allow-untyped-calls """Core SQL expression elements, including :class:`_expression.ClauseElement`, :class:`_expression.ColumnElement`, and derived classes. """ from __future__ import annotations from decimal import Decimal from enum import Enum import itertools import operator import re import typing from typing import AbstractSet from typing import Any from typing import Callable from typing import cast from typing import Dict from typing import FrozenSet from typing import Generic from typing import Iterable from typing import Iterator from typing import List from typing import Mapping from typing import Optional from typing import overload from typing import Sequence from typing import Set from typing import Tuple as typing_Tuple from typing import Type from typing import TYPE_CHECKING from typing import TypeVar from typing import Union from . import coercions from . import operators from . import roles from . import traversals from . import type_api from ._typing import has_schema_attr from ._typing import is_named_from_clause from ._typing import is_quoted_name from ._typing import is_tuple_type from .annotation import Annotated from .annotation import SupportsWrappingAnnotations from .base import _clone from .base import _expand_cloned from .base import _generative from .base import _NoArg from .base import Executable from .base import Generative from .base import HasMemoized from .base import Immutable from .base import NO_ARG from .base import SingletonConstant from .cache_key import MemoizedHasCacheKey from .cache_key import NO_CACHE from .coercions import _document_text_coercion # noqa from .operators import ColumnOperators from .traversals import HasCopyInternals from .visitors import cloned_traverse from .visitors import ExternallyTraversible from .visitors import InternalTraversal from .visitors import traverse from .visitors import Visitable from .. import exc from .. import inspection from .. import util from ..util import HasMemoized_ro_memoized_attribute from ..util import TypingOnly from ..util.typing import Literal from ..util.typing import ParamSpec from ..util.typing import Self if typing.TYPE_CHECKING: from ._typing import _ByArgument from ._typing import _ColumnExpressionArgument from ._typing import _ColumnExpressionOrStrLabelArgument from ._typing import _HasDialect from ._typing import _InfoType from ._typing import _PropagateAttrsType from ._typing import _TypeEngineArgument from .cache_key import _CacheKeyTraversalType from .cache_key import CacheKey from .compiler import Compiled from .compiler import SQLCompiler from .functions import FunctionElement from .operators import OperatorType from .schema import Column from .schema import DefaultGenerator from .schema import FetchedValue from .schema import ForeignKey from .selectable import _SelectIterable from .selectable import FromClause from .selectable import NamedFromClause from .selectable import TextualSelect from .sqltypes import TupleType from .type_api import TypeEngine from .visitors import _CloneCallableType from .visitors import _TraverseInternalsType from .visitors import anon_map from ..engine import Connection from ..engine import Dialect from ..engine.interfaces import _CoreMultiExecuteParams from ..engine.interfaces import CacheStats from ..engine.interfaces import CompiledCacheType from ..engine.interfaces import CoreExecuteOptionsParameter from ..engine.interfaces import SchemaTranslateMapType from ..engine.result import Result _NUMERIC = Union[float, Decimal] _NUMBER = Union[float, int, Decimal] _T = TypeVar("_T", bound="Any") _T_co = TypeVar("_T_co", bound=Any, covariant=True) _OPT = TypeVar("_OPT", bound="Any") _NT = TypeVar("_NT", bound="_NUMERIC") _NMT = TypeVar("_NMT", bound="_NUMBER") @overload def literal( value: Any, type_: _TypeEngineArgument[_T], literal_execute: bool = False, ) -> BindParameter[_T]: ... @overload def literal( value: _T, type_: None = None, literal_execute: bool = False, ) -> BindParameter[_T]: ... @overload def literal( value: Any, type_: Optional[_TypeEngineArgument[Any]] = None, literal_execute: bool = False, ) -> BindParameter[Any]: ... def literal( value: Any, type_: Optional[_TypeEngineArgument[Any]] = None, literal_execute: bool = False, ) -> BindParameter[Any]: r"""Return a literal clause, bound to a bind parameter. Literal clauses are created automatically when non- :class:`_expression.ClauseElement` objects (such as strings, ints, dates, etc.) are used in a comparison operation with a :class:`_expression.ColumnElement` subclass, such as a :class:`~sqlalchemy.schema.Column` object. Use this function to force the generation of a literal clause, which will be created as a :class:`BindParameter` with a bound value. :param value: the value to be bound. Can be any Python object supported by the underlying DB-API, or is translatable via the given type argument. :param type\_: an optional :class:`~sqlalchemy.types.TypeEngine` which will provide bind-parameter translation for this literal. :param literal_execute: optional bool, when True, the SQL engine will attempt to render the bound value directly in the SQL statement at execution time rather than providing as a parameter value. .. versionadded:: 2.0 """ return coercions.expect( roles.LiteralValueRole, value, type_=type_, literal_execute=literal_execute, ) def literal_column( text: str, type_: Optional[_TypeEngineArgument[_T]] = None ) -> ColumnClause[_T]: r"""Produce a :class:`.ColumnClause` object that has the :paramref:`_expression.column.is_literal` flag set to True. :func:`_expression.literal_column` is similar to :func:`_expression.column`, except that it is more often used as a "standalone" column expression that renders exactly as stated; while :func:`_expression.column` stores a string name that will be assumed to be part of a table and may be quoted as such, :func:`_expression.literal_column` can be that, or any other arbitrary column-oriented expression. :param text: the text of the expression; can be any SQL expression. Quoting rules will not be applied. To specify a column-name expression which should be subject to quoting rules, use the :func:`column` function. :param type\_: an optional :class:`~sqlalchemy.types.TypeEngine` object which will provide result-set translation and additional expression semantics for this column. If left as ``None`` the type will be :class:`.NullType`. .. seealso:: :func:`_expression.column` :func:`_expression.text` :ref:`tutorial_select_arbitrary_text` """ return ColumnClause(text, type_=type_, is_literal=True) class CompilerElement(Visitable): """base class for SQL elements that can be compiled to produce a SQL string. .. versionadded:: 2.0 """ __slots__ = () __visit_name__ = "compiler_element" supports_execution = False stringify_dialect = "default" @util.preload_module("sqlalchemy.engine.default") @util.preload_module("sqlalchemy.engine.url") def compile( self, bind: Optional[_HasDialect] = None, dialect: Optional[Dialect] = None, **kw: Any, ) -> Compiled: """Compile this SQL expression. The return value is a :class:`~.Compiled` object. Calling ``str()`` or ``unicode()`` on the returned value will yield a string representation of the result. The :class:`~.Compiled` object also can return a dictionary of bind parameter names and values using the ``params`` accessor. :param bind: An :class:`.Connection` or :class:`.Engine` which can provide a :class:`.Dialect` in order to generate a :class:`.Compiled` object. If the ``bind`` and ``dialect`` parameters are both omitted, a default SQL compiler is used. :param column_keys: Used for INSERT and UPDATE statements, a list of column names which should be present in the VALUES clause of the compiled statement. If ``None``, all columns from the target table object are rendered. :param dialect: A :class:`.Dialect` instance which can generate a :class:`.Compiled` object. This argument takes precedence over the ``bind`` argument. :param compile_kwargs: optional dictionary of additional parameters that will be passed through to the compiler within all "visit" methods. This allows any custom flag to be passed through to a custom compilation construct, for example. It is also used for the case of passing the ``literal_binds`` flag through:: from sqlalchemy.sql import table, column, select t = table('t', column('x')) s = select(t).where(t.c.x == 5) print(s.compile(compile_kwargs={"literal_binds": True})) .. seealso:: :ref:`faq_sql_expression_string` """ if dialect is None: if bind: dialect = bind.dialect elif self.stringify_dialect == "default": default = util.preloaded.engine_default dialect = default.StrCompileDialect() else: url = util.preloaded.engine_url dialect = url.URL.create( self.stringify_dialect ).get_dialect()() return self._compiler(dialect, **kw) def _compiler(self, dialect: Dialect, **kw: Any) -> Compiled: """Return a compiler appropriate for this ClauseElement, given a Dialect.""" if TYPE_CHECKING: assert isinstance(self, ClauseElement) return dialect.statement_compiler(dialect, self, **kw) def __str__(self) -> str: return str(self.compile()) @inspection._self_inspects class ClauseElement( SupportsWrappingAnnotations, MemoizedHasCacheKey, HasCopyInternals, ExternallyTraversible, CompilerElement, ): """Base class for elements of a programmatically constructed SQL expression. """ __visit_name__ = "clause" if TYPE_CHECKING: @util.memoized_property def _propagate_attrs(self) -> _PropagateAttrsType: """like annotations, however these propagate outwards liberally as SQL constructs are built, and are set up at construction time. """ ... else: _propagate_attrs = util.EMPTY_DICT @util.ro_memoized_property def description(self) -> Optional[str]: return None _is_clone_of: Optional[Self] = None is_clause_element = True is_selectable = False is_dml = False _is_column_element = False _is_keyed_column_element = False _is_table = False _gen_static_annotations_cache_key = False _is_textual = False _is_from_clause = False _is_returns_rows = False _is_text_clause = False _is_from_container = False _is_select_container = False _is_select_base = False _is_select_statement = False _is_bind_parameter = False _is_clause_list = False _is_lambda_element = False _is_singleton_constant = False _is_immutable = False _is_star = False @property def _order_by_label_element(self) -> Optional[Label[Any]]: return None _cache_key_traversal: _CacheKeyTraversalType = None negation_clause: ColumnElement[bool] if typing.TYPE_CHECKING: def get_children( self, *, omit_attrs: typing_Tuple[str, ...] = ..., **kw: Any ) -> Iterable[ClauseElement]: ... @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return [] def _set_propagate_attrs(self, values: Mapping[str, Any]) -> Self: # usually, self._propagate_attrs is empty here. one case where it's # not is a subquery against ORM select, that is then pulled as a # property of an aliased class. should all be good # assert not self._propagate_attrs self._propagate_attrs = util.immutabledict(values) return self def _clone(self, **kw: Any) -> Self: """Create a shallow copy of this ClauseElement. This method may be used by a generative API. Its also used as part of the "deep" copy afforded by a traversal that combines the _copy_internals() method. """ skip = self._memoized_keys c = self.__class__.__new__(self.__class__) if skip: # ensure this iteration remains atomic c.__dict__ = { k: v for k, v in self.__dict__.copy().items() if k not in skip } else: c.__dict__ = self.__dict__.copy() # this is a marker that helps to "equate" clauses to each other # when a Select returns its list of FROM clauses. the cloning # process leaves around a lot of remnants of the previous clause # typically in the form of column expressions still attached to the # old table. cc = self._is_clone_of c._is_clone_of = cc if cc is not None else self return c def _negate_in_binary(self, negated_op, original_op): """a hook to allow the right side of a binary expression to respond to a negation of the binary expression. Used for the special case of expanding bind parameter with IN. """ return self def _with_binary_element_type(self, type_): """in the context of binary expression, convert the type of this object to the one given. applies only to :class:`_expression.ColumnElement` classes. """ return self @property def _constructor(self): """return the 'constructor' for this ClauseElement. This is for the purposes for creating a new object of this type. Usually, its just the element's __class__. However, the "Annotated" version of the object overrides to return the class of its proxied element. """ return self.__class__ @HasMemoized.memoized_attribute def _cloned_set(self): """Return the set consisting all cloned ancestors of this ClauseElement. Includes this ClauseElement. This accessor tends to be used for FromClause objects to identify 'equivalent' FROM clauses, regardless of transformative operations. """ s = util.column_set() f: Optional[ClauseElement] = self # note this creates a cycle, asserted in test_memusage. however, # turning this into a plain @property adds tends of thousands of method # calls to Core / ORM performance tests, so the small overhead # introduced by the relatively small amount of short term cycles # produced here is preferable while f is not None: s.add(f) f = f._is_clone_of return s def _de_clone(self): while self._is_clone_of is not None: self = self._is_clone_of return self @property def entity_namespace(self): raise AttributeError( "This SQL expression has no entity namespace " "with which to filter from." ) def __getstate__(self): d = self.__dict__.copy() d.pop("_is_clone_of", None) d.pop("_generate_cache_key", None) return d def _execute_on_connection( self, connection: Connection, distilled_params: _CoreMultiExecuteParams, execution_options: CoreExecuteOptionsParameter, ) -> Result[Any]: if self.supports_execution: if TYPE_CHECKING: assert isinstance(self, Executable) return connection._execute_clauseelement( self, distilled_params, execution_options ) else: raise exc.ObjectNotExecutableError(self) def _execute_on_scalar( self, connection: Connection, distilled_params: _CoreMultiExecuteParams, execution_options: CoreExecuteOptionsParameter, ) -> Any: """an additional hook for subclasses to provide a different implementation for connection.scalar() vs. connection.execute(). .. versionadded:: 2.0 """ return self._execute_on_connection( connection, distilled_params, execution_options ).scalar() def _get_embedded_bindparams(self) -> Sequence[BindParameter[Any]]: """Return the list of :class:`.BindParameter` objects embedded in the object. This accomplishes the same purpose as ``visitors.traverse()`` or similar would provide, however by making use of the cache key it takes advantage of memoization of the key to result in fewer net method calls, assuming the statement is also going to be executed. """ key = self._generate_cache_key() if key is None: bindparams: List[BindParameter[Any]] = [] traverse(self, {}, {"bindparam": bindparams.append}) return bindparams else: return key.bindparams def unique_params( self, __optionaldict: Optional[Dict[str, Any]] = None, **kwargs: Any, ) -> Self: """Return a copy with :func:`_expression.bindparam` elements replaced. Same functionality as :meth:`_expression.ClauseElement.params`, except adds `unique=True` to affected bind parameters so that multiple statements can be used. """ return self._replace_params(True, __optionaldict, kwargs) def params( self, __optionaldict: Optional[Mapping[str, Any]] = None, **kwargs: Any, ) -> Self: """Return a copy with :func:`_expression.bindparam` elements replaced. Returns a copy of this ClauseElement with :func:`_expression.bindparam` elements replaced with values taken from the given dictionary:: >>> clause = column('x') + bindparam('foo') >>> print(clause.compile().params) {'foo':None} >>> print(clause.params({'foo':7}).compile().params) {'foo':7} """ return self._replace_params(False, __optionaldict, kwargs) def _replace_params( self, unique: bool, optionaldict: Optional[Mapping[str, Any]], kwargs: Dict[str, Any], ) -> Self: if optionaldict: kwargs.update(optionaldict) def visit_bindparam(bind: BindParameter[Any]) -> None: if bind.key in kwargs: bind.value = kwargs[bind.key] bind.required = False if unique: bind._convert_to_unique() return cloned_traverse( self, {"maintain_key": True, "detect_subquery_cols": True}, {"bindparam": visit_bindparam}, ) def compare(self, other: ClauseElement, **kw: Any) -> bool: r"""Compare this :class:`_expression.ClauseElement` to the given :class:`_expression.ClauseElement`. Subclasses should override the default behavior, which is a straight identity comparison. \**kw are arguments consumed by subclass ``compare()`` methods and may be used to modify the criteria for comparison (see :class:`_expression.ColumnElement`). """ return traversals.compare(self, other, **kw) def self_group( self, against: Optional[OperatorType] = None ) -> ClauseElement: """Apply a 'grouping' to this :class:`_expression.ClauseElement`. This method is overridden by subclasses to return a "grouping" construct, i.e. parenthesis. In particular it's used by "binary" expressions to provide a grouping around themselves when placed into a larger expression, as well as by :func:`_expression.select` constructs when placed into the FROM clause of another :func:`_expression.select`. (Note that subqueries should be normally created using the :meth:`_expression.Select.alias` method, as many platforms require nested SELECT statements to be named). As expressions are composed together, the application of :meth:`self_group` is automatic - end-user code should never need to use this method directly. Note that SQLAlchemy's clause constructs take operator precedence into account - so parenthesis might not be needed, for example, in an expression like ``x OR (y AND z)`` - AND takes precedence over OR. The base :meth:`self_group` method of :class:`_expression.ClauseElement` just returns self. """ return self def _ungroup(self) -> ClauseElement: """Return this :class:`_expression.ClauseElement` without any groupings. """ return self def _compile_w_cache( self, dialect: Dialect, *, compiled_cache: Optional[CompiledCacheType], column_keys: List[str], for_executemany: bool = False, schema_translate_map: Optional[SchemaTranslateMapType] = None, **kw: Any, ) -> typing_Tuple[ Compiled, Optional[Sequence[BindParameter[Any]]], CacheStats ]: elem_cache_key: Optional[CacheKey] if compiled_cache is not None and dialect._supports_statement_cache: elem_cache_key = self._generate_cache_key() else: elem_cache_key = None if elem_cache_key is not None: if TYPE_CHECKING: assert compiled_cache is not None cache_key, extracted_params = elem_cache_key key = ( dialect, cache_key, tuple(column_keys), bool(schema_translate_map), for_executemany, ) compiled_sql = compiled_cache.get(key) if compiled_sql is None: cache_hit = dialect.CACHE_MISS compiled_sql = self._compiler( dialect, cache_key=elem_cache_key, column_keys=column_keys, for_executemany=for_executemany, schema_translate_map=schema_translate_map, **kw, ) compiled_cache[key] = compiled_sql else: cache_hit = dialect.CACHE_HIT else: extracted_params = None compiled_sql = self._compiler( dialect, cache_key=elem_cache_key, column_keys=column_keys, for_executemany=for_executemany, schema_translate_map=schema_translate_map, **kw, ) if not dialect._supports_statement_cache: cache_hit = dialect.NO_DIALECT_SUPPORT elif compiled_cache is None: cache_hit = dialect.CACHING_DISABLED else: cache_hit = dialect.NO_CACHE_KEY return compiled_sql, extracted_params, cache_hit def __invert__(self): # undocumented element currently used by the ORM for # relationship.contains() if hasattr(self, "negation_clause"): return self.negation_clause else: return self._negate() def _negate(self) -> ClauseElement: grouped = self.self_group(against=operators.inv) assert isinstance(grouped, ColumnElement) return UnaryExpression(grouped, operator=operators.inv) def __bool__(self): raise TypeError("Boolean value of this clause is not defined") def __repr__(self): friendly = self.description if friendly is None: return object.__repr__(self) else: return "<%s.%s at 0x%x; %s>" % ( self.__module__, self.__class__.__name__, id(self), friendly, ) class DQLDMLClauseElement(ClauseElement): """represents a :class:`.ClauseElement` that compiles to a DQL or DML expression, not DDL. .. versionadded:: 2.0 """ if typing.TYPE_CHECKING: def _compiler(self, dialect: Dialect, **kw: Any) -> SQLCompiler: """Return a compiler appropriate for this ClauseElement, given a Dialect.""" ... def compile( # noqa: A001 self, bind: Optional[_HasDialect] = None, dialect: Optional[Dialect] = None, **kw: Any, ) -> SQLCompiler: ... class CompilerColumnElement( roles.DMLColumnRole, roles.DDLConstraintColumnRole, roles.ColumnsClauseRole, CompilerElement, ): """A compiler-only column element used for ad-hoc string compilations. .. versionadded:: 2.0 """ __slots__ = () _propagate_attrs = util.EMPTY_DICT _is_collection_aggregate = False # SQLCoreOperations should be suiting the ExpressionElementRole # and ColumnsClauseRole. however the MRO issues become too elaborate # at the moment. class SQLCoreOperations(Generic[_T_co], ColumnOperators, TypingOnly): __slots__ = () # annotations for comparison methods # these are from operators->Operators / ColumnOperators, # redefined with the specific types returned by ColumnElement hierarchies if typing.TYPE_CHECKING: @util.non_memoized_property def _propagate_attrs(self) -> _PropagateAttrsType: ... def operate( self, op: OperatorType, *other: Any, **kwargs: Any ) -> ColumnElement[Any]: ... def reverse_operate( self, op: OperatorType, other: Any, **kwargs: Any ) -> ColumnElement[Any]: ... @overload def op( self, opstring: str, precedence: int = ..., is_comparison: bool = ..., *, return_type: _TypeEngineArgument[_OPT], python_impl: Optional[Callable[..., Any]] = None, ) -> Callable[[Any], BinaryExpression[_OPT]]: ... @overload def op( self, opstring: str, precedence: int = ..., is_comparison: bool = ..., return_type: Optional[_TypeEngineArgument[Any]] = ..., python_impl: Optional[Callable[..., Any]] = ..., ) -> Callable[[Any], BinaryExpression[Any]]: ... def op( self, opstring: str, precedence: int = 0, is_comparison: bool = False, return_type: Optional[_TypeEngineArgument[Any]] = None, python_impl: Optional[Callable[..., Any]] = None, ) -> Callable[[Any], BinaryExpression[Any]]: ... def bool_op( self, opstring: str, precedence: int = 0, python_impl: Optional[Callable[..., Any]] = None, ) -> Callable[[Any], BinaryExpression[bool]]: ... def __and__(self, other: Any) -> BooleanClauseList: ... def __or__(self, other: Any) -> BooleanClauseList: ... def __invert__(self) -> ColumnElement[_T_co]: ... def __lt__(self, other: Any) -> ColumnElement[bool]: ... def __le__(self, other: Any) -> ColumnElement[bool]: ... # declare also that this class has an hash method otherwise # it may be assumed to be None by type checkers since the # object defines __eq__ and python sets it to None in that case: # https://docs.python.org/3/reference/datamodel.html#object.__hash__ def __hash__(self) -> int: ... def __eq__(self, other: Any) -> ColumnElement[bool]: # type: ignore[override] # noqa: E501 ... def __ne__(self, other: Any) -> ColumnElement[bool]: # type: ignore[override] # noqa: E501 ... def is_distinct_from(self, other: Any) -> ColumnElement[bool]: ... def is_not_distinct_from(self, other: Any) -> ColumnElement[bool]: ... def __gt__(self, other: Any) -> ColumnElement[bool]: ... def __ge__(self, other: Any) -> ColumnElement[bool]: ... def __neg__(self) -> UnaryExpression[_T_co]: ... def __contains__(self, other: Any) -> ColumnElement[bool]: ... def __getitem__(self, index: Any) -> ColumnElement[Any]: ... @overload def __lshift__(self: _SQO[int], other: Any) -> ColumnElement[int]: ... @overload def __lshift__(self, other: Any) -> ColumnElement[Any]: ... def __lshift__(self, other: Any) -> ColumnElement[Any]: ... @overload def __rshift__(self: _SQO[int], other: Any) -> ColumnElement[int]: ... @overload def __rshift__(self, other: Any) -> ColumnElement[Any]: ... def __rshift__(self, other: Any) -> ColumnElement[Any]: ... @overload def concat(self: _SQO[str], other: Any) -> ColumnElement[str]: ... @overload def concat(self, other: Any) -> ColumnElement[Any]: ... def concat(self, other: Any) -> ColumnElement[Any]: ... def like( self, other: Any, escape: Optional[str] = None ) -> BinaryExpression[bool]: ... def ilike( self, other: Any, escape: Optional[str] = None ) -> BinaryExpression[bool]: ... def bitwise_xor(self, other: Any) -> BinaryExpression[Any]: ... def bitwise_or(self, other: Any) -> BinaryExpression[Any]: ... def bitwise_and(self, other: Any) -> BinaryExpression[Any]: ... def bitwise_not(self) -> UnaryExpression[_T_co]: ... def bitwise_lshift(self, other: Any) -> BinaryExpression[Any]: ... def bitwise_rshift(self, other: Any) -> BinaryExpression[Any]: ... def in_( self, other: Union[ Iterable[Any], BindParameter[Any], roles.InElementRole ], ) -> BinaryExpression[bool]: ... def not_in( self, other: Union[ Iterable[Any], BindParameter[Any], roles.InElementRole ], ) -> BinaryExpression[bool]: ... def notin_( self, other: Union[ Iterable[Any], BindParameter[Any], roles.InElementRole ], ) -> BinaryExpression[bool]: ... def not_like( self, other: Any, escape: Optional[str] = None ) -> BinaryExpression[bool]: ... def notlike( self, other: Any, escape: Optional[str] = None ) -> BinaryExpression[bool]: ... def not_ilike( self, other: Any, escape: Optional[str] = None ) -> BinaryExpression[bool]: ... def notilike( self, other: Any, escape: Optional[str] = None ) -> BinaryExpression[bool]: ... def is_(self, other: Any) -> BinaryExpression[bool]: ... def is_not(self, other: Any) -> BinaryExpression[bool]: ... def isnot(self, other: Any) -> BinaryExpression[bool]: ... def startswith( self, other: Any, escape: Optional[str] = None, autoescape: bool = False, ) -> ColumnElement[bool]: ... def istartswith( self, other: Any, escape: Optional[str] = None, autoescape: bool = False, ) -> ColumnElement[bool]: ... def endswith( self, other: Any, escape: Optional[str] = None, autoescape: bool = False, ) -> ColumnElement[bool]: ... def iendswith( self, other: Any, escape: Optional[str] = None, autoescape: bool = False, ) -> ColumnElement[bool]: ... def contains(self, other: Any, **kw: Any) -> ColumnElement[bool]: ... def icontains(self, other: Any, **kw: Any) -> ColumnElement[bool]: ... def match(self, other: Any, **kwargs: Any) -> ColumnElement[bool]: ... def regexp_match( self, pattern: Any, flags: Optional[str] = None ) -> ColumnElement[bool]: ... def regexp_replace( self, pattern: Any, replacement: Any, flags: Optional[str] = None ) -> ColumnElement[str]: ... def desc(self) -> UnaryExpression[_T_co]: ... def asc(self) -> UnaryExpression[_T_co]: ... def nulls_first(self) -> UnaryExpression[_T_co]: ... def nullsfirst(self) -> UnaryExpression[_T_co]: ... def nulls_last(self) -> UnaryExpression[_T_co]: ... def nullslast(self) -> UnaryExpression[_T_co]: ... def collate(self, collation: str) -> CollationClause: ... def between( self, cleft: Any, cright: Any, symmetric: bool = False ) -> BinaryExpression[bool]: ... def distinct(self: _SQO[_T_co]) -> UnaryExpression[_T_co]: ... def any_(self) -> CollectionAggregate[Any]: ... def all_(self) -> CollectionAggregate[Any]: ... # numeric overloads. These need more tweaking # in particular they all need to have a variant for Optiona[_T] # because Optional only applies to the data side, not the expression # side @overload def __add__( self: _SQO[_NMT], other: Any, ) -> ColumnElement[_NMT]: ... @overload def __add__( self: _SQO[str], other: Any, ) -> ColumnElement[str]: ... @overload def __add__(self, other: Any) -> ColumnElement[Any]: ... def __add__(self, other: Any) -> ColumnElement[Any]: ... @overload def __radd__(self: _SQO[_NMT], other: Any) -> ColumnElement[_NMT]: ... @overload def __radd__(self: _SQO[str], other: Any) -> ColumnElement[str]: ... def __radd__(self, other: Any) -> ColumnElement[Any]: ... @overload def __sub__( self: _SQO[_NMT], other: Any, ) -> ColumnElement[_NMT]: ... @overload def __sub__(self, other: Any) -> ColumnElement[Any]: ... def __sub__(self, other: Any) -> ColumnElement[Any]: ... @overload def __rsub__( self: _SQO[_NMT], other: Any, ) -> ColumnElement[_NMT]: ... @overload def __rsub__(self, other: Any) -> ColumnElement[Any]: ... def __rsub__(self, other: Any) -> ColumnElement[Any]: ... @overload def __mul__( self: _SQO[_NMT], other: Any, ) -> ColumnElement[_NMT]: ... @overload def __mul__(self, other: Any) -> ColumnElement[Any]: ... def __mul__(self, other: Any) -> ColumnElement[Any]: ... @overload def __rmul__( self: _SQO[_NMT], other: Any, ) -> ColumnElement[_NMT]: ... @overload def __rmul__(self, other: Any) -> ColumnElement[Any]: ... def __rmul__(self, other: Any) -> ColumnElement[Any]: ... @overload def __mod__(self: _SQO[_NMT], other: Any) -> ColumnElement[_NMT]: ... @overload def __mod__(self, other: Any) -> ColumnElement[Any]: ... def __mod__(self, other: Any) -> ColumnElement[Any]: ... @overload def __rmod__(self: _SQO[_NMT], other: Any) -> ColumnElement[_NMT]: ... @overload def __rmod__(self, other: Any) -> ColumnElement[Any]: ... def __rmod__(self, other: Any) -> ColumnElement[Any]: ... @overload def __truediv__( self: _SQO[int], other: Any ) -> ColumnElement[_NUMERIC]: ... @overload def __truediv__(self: _SQO[_NT], other: Any) -> ColumnElement[_NT]: ... @overload def __truediv__(self, other: Any) -> ColumnElement[Any]: ... def __truediv__(self, other: Any) -> ColumnElement[Any]: ... @overload def __rtruediv__( self: _SQO[_NMT], other: Any ) -> ColumnElement[_NUMERIC]: ... @overload def __rtruediv__(self, other: Any) -> ColumnElement[Any]: ... def __rtruediv__(self, other: Any) -> ColumnElement[Any]: ... @overload def __floordiv__( self: _SQO[_NMT], other: Any ) -> ColumnElement[_NMT]: ... @overload def __floordiv__(self, other: Any) -> ColumnElement[Any]: ... def __floordiv__(self, other: Any) -> ColumnElement[Any]: ... @overload def __rfloordiv__( self: _SQO[_NMT], other: Any ) -> ColumnElement[_NMT]: ... @overload def __rfloordiv__(self, other: Any) -> ColumnElement[Any]: ... def __rfloordiv__(self, other: Any) -> ColumnElement[Any]: ... class SQLColumnExpression( SQLCoreOperations[_T_co], roles.ExpressionElementRole[_T_co], TypingOnly ): """A type that may be used to indicate any SQL column element or object that acts in place of one. :class:`.SQLColumnExpression` is a base of :class:`.ColumnElement`, as well as within the bases of ORM elements such as :class:`.InstrumentedAttribute`, and may be used in :pep:`484` typing to indicate arguments or return values that should behave as column expressions. .. versionadded:: 2.0.0b4 """ __slots__ = () _SQO = SQLCoreOperations class ColumnElement( roles.ColumnArgumentOrKeyRole, roles.StatementOptionRole, roles.WhereHavingRole, roles.BinaryElementRole[_T], roles.OrderByRole, roles.ColumnsClauseRole, roles.LimitOffsetRole, roles.DMLColumnRole, roles.DDLConstraintColumnRole, roles.DDLExpressionRole, SQLColumnExpression[_T], DQLDMLClauseElement, ): """Represent a column-oriented SQL expression suitable for usage in the "columns" clause, WHERE clause etc. of a statement. While the most familiar kind of :class:`_expression.ColumnElement` is the :class:`_schema.Column` object, :class:`_expression.ColumnElement` serves as the basis for any unit that may be present in a SQL expression, including the expressions themselves, SQL functions, bound parameters, literal expressions, keywords such as ``NULL``, etc. :class:`_expression.ColumnElement` is the ultimate base class for all such elements. A wide variety of SQLAlchemy Core functions work at the SQL expression level, and are intended to accept instances of :class:`_expression.ColumnElement` as arguments. These functions will typically document that they accept a "SQL expression" as an argument. What this means in terms of SQLAlchemy usually refers to an input which is either already in the form of a :class:`_expression.ColumnElement` object, or a value which can be **coerced** into one. The coercion rules followed by most, but not all, SQLAlchemy Core functions with regards to SQL expressions are as follows: * a literal Python value, such as a string, integer or floating point value, boolean, datetime, ``Decimal`` object, or virtually any other Python object, will be coerced into a "literal bound value". This generally means that a :func:`.bindparam` will be produced featuring the given value embedded into the construct; the resulting :class:`.BindParameter` object is an instance of :class:`_expression.ColumnElement`. The Python value will ultimately be sent to the DBAPI at execution time as a parameterized argument to the ``execute()`` or ``executemany()`` methods, after SQLAlchemy type-specific converters (e.g. those provided by any associated :class:`.TypeEngine` objects) are applied to the value. * any special object value, typically ORM-level constructs, which feature an accessor called ``__clause_element__()``. The Core expression system looks for this method when an object of otherwise unknown type is passed to a function that is looking to coerce the argument into a :class:`_expression.ColumnElement` and sometimes a :class:`_expression.SelectBase` expression. It is used within the ORM to convert from ORM-specific objects like mapped classes and mapped attributes into Core expression objects. * The Python ``None`` value is typically interpreted as ``NULL``, which in SQLAlchemy Core produces an instance of :func:`.null`. A :class:`_expression.ColumnElement` provides the ability to generate new :class:`_expression.ColumnElement` objects using Python expressions. This means that Python operators such as ``==``, ``!=`` and ``<`` are overloaded to mimic SQL operations, and allow the instantiation of further :class:`_expression.ColumnElement` instances which are composed from other, more fundamental :class:`_expression.ColumnElement` objects. For example, two :class:`.ColumnClause` objects can be added together with the addition operator ``+`` to produce a :class:`.BinaryExpression`. Both :class:`.ColumnClause` and :class:`.BinaryExpression` are subclasses of :class:`_expression.ColumnElement`: .. sourcecode:: pycon+sql >>> from sqlalchemy.sql import column >>> column('a') + column('b') <sqlalchemy.sql.expression.BinaryExpression object at 0x101029dd0> >>> print(column('a') + column('b')) {printsql}a + b .. seealso:: :class:`_schema.Column` :func:`_expression.column` """ __visit_name__ = "column_element" primary_key: bool = False _is_clone_of: Optional[ColumnElement[_T]] _is_column_element = True _insert_sentinel: bool = False _omit_from_statements = False _is_collection_aggregate = False foreign_keys: AbstractSet[ForeignKey] = frozenset() @util.memoized_property def _proxies(self) -> List[ColumnElement[Any]]: return [] @util.non_memoized_property def _tq_label(self) -> Optional[str]: """The named label that can be used to target this column in a result set in a "table qualified" context. This label is almost always the label used when rendering <expr> AS <label> in a SELECT statement when using the LABEL_STYLE_TABLENAME_PLUS_COL label style, which is what the legacy ORM ``Query`` object uses as well. For a regular Column bound to a Table, this is typically the label <tablename>_<columnname>. For other constructs, different rules may apply, such as anonymized labels and others. .. versionchanged:: 1.4.21 renamed from ``._label`` """ return None key: Optional[str] = None """The 'key' that in some circumstances refers to this object in a Python namespace. This typically refers to the "key" of the column as present in the ``.c`` collection of a selectable, e.g. ``sometable.c["somekey"]`` would return a :class:`_schema.Column` with a ``.key`` of "somekey". """ @HasMemoized.memoized_attribute def _tq_key_label(self) -> Optional[str]: """A label-based version of 'key' that in some circumstances refers to this object in a Python namespace. _tq_key_label comes into play when a select() statement is constructed with apply_labels(); in this case, all Column objects in the ``.c`` collection are rendered as <tablename>_<columnname> in SQL; this is essentially the value of ._label. But to locate those columns in the ``.c`` collection, the name is along the lines of <tablename>_<key>; that's the typical value of .key_label. .. versionchanged:: 1.4.21 renamed from ``._key_label`` """ return self._proxy_key @property def _key_label(self) -> Optional[str]: """legacy; renamed to _tq_key_label""" return self._tq_key_label @property def _label(self) -> Optional[str]: """legacy; renamed to _tq_label""" return self._tq_label @property def _non_anon_label(self) -> Optional[str]: """the 'name' that naturally applies this element when rendered in SQL. Concretely, this is the "name" of a column or a label in a SELECT statement; ``<columnname>`` and ``<labelname>`` below:: SELECT <columnmame> FROM table SELECT column AS <labelname> FROM table Above, the two names noted will be what's present in the DBAPI ``cursor.description`` as the names. If this attribute returns ``None``, it means that the SQL element as written does not have a 100% fully predictable "name" that would appear in the ``cursor.description``. Examples include SQL functions, CAST functions, etc. While such things do return names in ``cursor.description``, they are only predictable on a database-specific basis; e.g. an expression like ``MAX(table.col)`` may appear as the string ``max`` on one database (like PostgreSQL) or may appear as the whole expression ``max(table.col)`` on SQLite. The default implementation looks for a ``.name`` attribute on the object, as has been the precedent established in SQLAlchemy for many years. An exception is made on the ``FunctionElement`` subclass so that the return value is always ``None``. .. versionadded:: 1.4.21 """ return getattr(self, "name", None) _render_label_in_columns_clause = True """A flag used by select._columns_plus_names that helps to determine we are actually going to render in terms of "SELECT <col> AS <label>". This flag can be returned as False for some Column objects that want to be rendered as simple "SELECT <col>"; typically columns that don't have any parent table and are named the same as what the label would be in any case. """ _allow_label_resolve = True """A flag that can be flipped to prevent a column from being resolvable by string label name. The joined eager loader strategy in the ORM uses this, for example. """ _is_implicitly_boolean = False _alt_names: Sequence[str] = () @overload def self_group(self, against: None = None) -> ColumnElement[_T]: ... @overload def self_group( self, against: Optional[OperatorType] = None ) -> ColumnElement[Any]: ... def self_group( self, against: Optional[OperatorType] = None ) -> ColumnElement[Any]: if ( against in (operators.and_, operators.or_, operators._asbool) and self.type._type_affinity is type_api.BOOLEANTYPE._type_affinity ): return AsBoolean(self, operators.is_true, operators.is_false) elif against in (operators.any_op, operators.all_op): return Grouping(self) else: return self @overload def _negate(self: ColumnElement[bool]) -> ColumnElement[bool]: ... @overload def _negate(self: ColumnElement[_T]) -> ColumnElement[_T]: ... def _negate(self) -> ColumnElement[Any]: if self.type._type_affinity is type_api.BOOLEANTYPE._type_affinity: return AsBoolean(self, operators.is_false, operators.is_true) else: grouped = self.self_group(against=operators.inv) assert isinstance(grouped, ColumnElement) return UnaryExpression( grouped, operator=operators.inv, wraps_column_expression=True ) type: TypeEngine[_T] if not TYPE_CHECKING: @util.memoized_property def type(self) -> TypeEngine[_T]: # noqa: A001 # used for delayed setup of # type_api return type_api.NULLTYPE @HasMemoized.memoized_attribute def comparator(self) -> TypeEngine.Comparator[_T]: try: comparator_factory = self.type.comparator_factory except AttributeError as err: raise TypeError( "Object %r associated with '.type' attribute " "is not a TypeEngine class or object" % self.type ) from err else: return comparator_factory(self) def __setstate__(self, state): self.__dict__.update(state) def __getattr__(self, key: str) -> Any: try: return getattr(self.comparator, key) except AttributeError as err: raise AttributeError( "Neither %r object nor %r object has an attribute %r" % ( type(self).__name__, type(self.comparator).__name__, key, ) ) from err def operate( self, op: operators.OperatorType, *other: Any, **kwargs: Any, ) -> ColumnElement[Any]: return op(self.comparator, *other, **kwargs) # type: ignore[no-any-return] # noqa: E501 def reverse_operate( self, op: operators.OperatorType, other: Any, **kwargs: Any ) -> ColumnElement[Any]: return op(other, self.comparator, **kwargs) # type: ignore[no-any-return] # noqa: E501 def _bind_param( self, operator: operators.OperatorType, obj: Any, type_: Optional[TypeEngine[_T]] = None, expanding: bool = False, ) -> BindParameter[_T]: return BindParameter( None, obj, _compared_to_operator=operator, type_=type_, _compared_to_type=self.type, unique=True, expanding=expanding, ) @property def expression(self) -> ColumnElement[Any]: """Return a column expression. Part of the inspection interface; returns self. """ return self @property def _select_iterable(self) -> _SelectIterable: return (self,) @util.memoized_property def base_columns(self) -> FrozenSet[ColumnElement[Any]]: return frozenset(c for c in self.proxy_set if not c._proxies) @util.memoized_property def proxy_set(self) -> FrozenSet[ColumnElement[Any]]: """set of all columns we are proxying as of 2.0 this is explicitly deannotated columns. previously it was effectively deannotated columns but wasn't enforced. annotated columns should basically not go into sets if at all possible because their hashing behavior is very non-performant. """ return frozenset([self._deannotate()]).union( itertools.chain(*[c.proxy_set for c in self._proxies]) ) @util.memoized_property def _expanded_proxy_set(self) -> FrozenSet[ColumnElement[Any]]: return frozenset(_expand_cloned(self.proxy_set)) def _uncached_proxy_list(self) -> List[ColumnElement[Any]]: """An 'uncached' version of proxy set. This list includes annotated columns which perform very poorly in set operations. """ return [self] + list( itertools.chain(*[c._uncached_proxy_list() for c in self._proxies]) ) def shares_lineage(self, othercolumn: ColumnElement[Any]) -> bool: """Return True if the given :class:`_expression.ColumnElement` has a common ancestor to this :class:`_expression.ColumnElement`.""" return bool(self.proxy_set.intersection(othercolumn.proxy_set)) def _compare_name_for_result(self, other: ColumnElement[Any]) -> bool: """Return True if the given column element compares to this one when targeting within a result row.""" return ( hasattr(other, "name") and hasattr(self, "name") and other.name == self.name ) @HasMemoized.memoized_attribute def _proxy_key(self) -> Optional[str]: if self._annotations and "proxy_key" in self._annotations: return cast(str, self._annotations["proxy_key"]) name = self.key if not name: # there's a bit of a seeming contradiction which is that the # "_non_anon_label" of a column can in fact be an # "_anonymous_label"; this is when it's on a column that is # proxying for an anonymous expression in a subquery. name = self._non_anon_label if isinstance(name, _anonymous_label): return None else: return name @HasMemoized.memoized_attribute def _expression_label(self) -> Optional[str]: """a suggested label to use in the case that the column has no name, which should be used if possible as the explicit 'AS <label>' where this expression would normally have an anon label. this is essentially mostly what _proxy_key does except it returns None if the column has a normal name that can be used. """ if getattr(self, "name", None) is not None: return None elif self._annotations and "proxy_key" in self._annotations: return cast(str, self._annotations["proxy_key"]) else: return None def _make_proxy( self, selectable: FromClause, *, name: Optional[str] = None, key: Optional[str] = None, name_is_truncatable: bool = False, compound_select_cols: Optional[Sequence[ColumnElement[Any]]] = None, **kw: Any, ) -> typing_Tuple[str, ColumnClause[_T]]: """Create a new :class:`_expression.ColumnElement` representing this :class:`_expression.ColumnElement` as it appears in the select list of a descending selectable. """ if name is None: name = self._anon_name_label if key is None: key = self._proxy_key else: key = name assert key is not None co: ColumnClause[_T] = ColumnClause( ( coercions.expect(roles.TruncatedLabelRole, name) if name_is_truncatable else name ), type_=getattr(self, "type", None), _selectable=selectable, ) co._propagate_attrs = selectable._propagate_attrs if compound_select_cols: co._proxies = list(compound_select_cols) else: co._proxies = [self] if selectable._is_clone_of is not None: co._is_clone_of = selectable._is_clone_of.columns.get(key) return key, co def cast(self, type_: _TypeEngineArgument[_OPT]) -> Cast[_OPT]: """Produce a type cast, i.e. ``CAST(<expression> AS <type>)``. This is a shortcut to the :func:`_expression.cast` function. .. seealso:: :ref:`tutorial_casts` :func:`_expression.cast` :func:`_expression.type_coerce` """ return Cast(self, type_) def label(self, name: Optional[str]) -> Label[_T]: """Produce a column label, i.e. ``<columnname> AS <name>``. This is a shortcut to the :func:`_expression.label` function. If 'name' is ``None``, an anonymous label name will be generated. """ return Label(name, self, self.type) def _anon_label( self, seed: Optional[str], add_hash: Optional[int] = None ) -> _anonymous_label: while self._is_clone_of is not None: self = self._is_clone_of # as of 1.4 anonymous label for ColumnElement uses hash(), not id(), # as the identifier, because a column and its annotated version are # the same thing in a SQL statement hash_value = hash(self) if add_hash: # this path is used for disambiguating anon labels that would # otherwise be the same name for the same element repeated. # an additional numeric value is factored in for each label. # shift hash(self) (which is id(self), typically 8 byte integer) # 16 bits leftward. fill extra add_hash on right assert add_hash < (2 << 15) assert seed hash_value = (hash_value << 16) | add_hash # extra underscore is added for labels with extra hash # values, to isolate the "deduped anon" namespace from the # regular namespace. eliminates chance of these # manufactured hash values overlapping with regular ones for some # undefined python interpreter seed = seed + "_" if isinstance(seed, _anonymous_label): return _anonymous_label.safe_construct( hash_value, "", enclosing_label=seed ) return _anonymous_label.safe_construct(hash_value, seed or "anon") @util.memoized_property def _anon_name_label(self) -> str: """Provides a constant 'anonymous label' for this ColumnElement. This is a label() expression which will be named at compile time. The same label() is returned each time ``anon_label`` is called so that expressions can reference ``anon_label`` multiple times, producing the same label name at compile time. The compiler uses this function automatically at compile time for expressions that are known to be 'unnamed' like binary expressions and function calls. .. versionchanged:: 1.4.9 - this attribute was not intended to be public and is renamed to _anon_name_label. anon_name exists for backwards compat """ name = getattr(self, "name", None) return self._anon_label(name) @util.memoized_property def _anon_key_label(self) -> _anonymous_label: """Provides a constant 'anonymous key label' for this ColumnElement. Compare to ``anon_label``, except that the "key" of the column, if available, is used to generate the label. This is used when a deduplicating key is placed into the columns collection of a selectable. .. versionchanged:: 1.4.9 - this attribute was not intended to be public and is renamed to _anon_key_label. anon_key_label exists for backwards compat """ return self._anon_label(self._proxy_key) @property @util.deprecated( "1.4", "The :attr:`_expression.ColumnElement.anon_label` attribute is now " "private, and the public accessor is deprecated.", ) def anon_label(self) -> str: return self._anon_name_label @property @util.deprecated( "1.4", "The :attr:`_expression.ColumnElement.anon_key_label` attribute is " "now private, and the public accessor is deprecated.", ) def anon_key_label(self) -> str: return self._anon_key_label def _dedupe_anon_label_idx(self, idx: int) -> str: """label to apply to a column that is anon labeled, but repeated in the SELECT, so that we have to make an "extra anon" label that disambiguates it from the previous appearance. these labels come out like "foo_bar_id__1" and have double underscores in them. """ label = getattr(self, "name", None) # current convention is that if the element doesn't have a # ".name" (usually because it is not NamedColumn), we try to # use a "table qualified" form for the "dedupe anon" label, # based on the notion that a label like # "CAST(casttest.v1 AS DECIMAL) AS casttest_v1__1" looks better than # "CAST(casttest.v1 AS DECIMAL) AS anon__1" if label is None: return self._dedupe_anon_tq_label_idx(idx) else: return self._anon_label(label, add_hash=idx) @util.memoized_property def _anon_tq_label(self) -> _anonymous_label: return self._anon_label(getattr(self, "_tq_label", None)) @util.memoized_property def _anon_tq_key_label(self) -> _anonymous_label: return self._anon_label(getattr(self, "_tq_key_label", None)) def _dedupe_anon_tq_label_idx(self, idx: int) -> _anonymous_label: label = getattr(self, "_tq_label", None) or "anon" return self._anon_label(label, add_hash=idx) class KeyedColumnElement(ColumnElement[_T]): """ColumnElement where ``.key`` is non-None.""" _is_keyed_column_element = True key: str class WrapsColumnExpression(ColumnElement[_T]): """Mixin that defines a :class:`_expression.ColumnElement` as a wrapper with special labeling behavior for an expression that already has a name. .. versionadded:: 1.4 .. seealso:: :ref:`change_4449` """ @property def wrapped_column_expression(self) -> ColumnElement[_T]: raise NotImplementedError() @util.non_memoized_property def _tq_label(self) -> Optional[str]: wce = self.wrapped_column_expression if hasattr(wce, "_tq_label"): return wce._tq_label else: return None @property def _label(self) -> Optional[str]: return self._tq_label @property def _non_anon_label(self) -> Optional[str]: return None @util.non_memoized_property def _anon_name_label(self) -> str: wce = self.wrapped_column_expression # this logic tries to get the WrappedColumnExpression to render # with "<expr> AS <name>", where "<name>" is the natural name # within the expression itself. e.g. "CAST(table.foo) AS foo". if not wce._is_text_clause: nal = wce._non_anon_label if nal: return nal elif hasattr(wce, "_anon_name_label"): return wce._anon_name_label return super()._anon_name_label def _dedupe_anon_label_idx(self, idx: int) -> str: wce = self.wrapped_column_expression nal = wce._non_anon_label if nal: return self._anon_label(nal + "_") else: return self._dedupe_anon_tq_label_idx(idx) @property def _proxy_key(self): wce = self.wrapped_column_expression if not wce._is_text_clause: return wce._proxy_key return super()._proxy_key class BindParameter(roles.InElementRole, KeyedColumnElement[_T]): r"""Represent a "bound expression". :class:`.BindParameter` is invoked explicitly using the :func:`.bindparam` function, as in:: from sqlalchemy import bindparam stmt = select(users_table).where( users_table.c.name == bindparam("username") ) Detailed discussion of how :class:`.BindParameter` is used is at :func:`.bindparam`. .. seealso:: :func:`.bindparam` """ __visit_name__ = "bindparam" _traverse_internals: _TraverseInternalsType = [ ("key", InternalTraversal.dp_anon_name), ("type", InternalTraversal.dp_type), ("callable", InternalTraversal.dp_plain_dict), ("value", InternalTraversal.dp_plain_obj), ("literal_execute", InternalTraversal.dp_boolean), ] key: str type: TypeEngine[_T] value: Optional[_T] _is_crud = False _is_bind_parameter = True _key_is_anon = False # bindparam implements its own _gen_cache_key() method however # we check subclasses for this flag, else no cache key is generated inherit_cache = True def __init__( self, key: Optional[str], value: Any = _NoArg.NO_ARG, type_: Optional[_TypeEngineArgument[_T]] = None, unique: bool = False, required: Union[bool, Literal[_NoArg.NO_ARG]] = _NoArg.NO_ARG, quote: Optional[bool] = None, callable_: Optional[Callable[[], Any]] = None, expanding: bool = False, isoutparam: bool = False, literal_execute: bool = False, _compared_to_operator: Optional[OperatorType] = None, _compared_to_type: Optional[TypeEngine[Any]] = None, _is_crud: bool = False, ): if required is _NoArg.NO_ARG: required = value is _NoArg.NO_ARG and callable_ is None if value is _NoArg.NO_ARG: value = None if quote is not None: key = quoted_name.construct(key, quote) if unique: self.key = _anonymous_label.safe_construct( id(self), ( key if key is not None and not isinstance(key, _anonymous_label) else "param" ), sanitize_key=True, ) self._key_is_anon = True elif key: self.key = key else: self.key = _anonymous_label.safe_construct(id(self), "param") self._key_is_anon = True # identifying key that won't change across # clones, used to identify the bind's logical # identity self._identifying_key = self.key # key that was passed in the first place, used to # generate new keys self._orig_key = key or "param" self.unique = unique self.value = value self.callable = callable_ self.isoutparam = isoutparam self.required = required # indicate an "expanding" parameter; the compiler sets this # automatically in the compiler _render_in_expr_w_bindparam method # for an IN expression self.expanding = expanding # this is another hint to help w/ expanding and is typically # set in the compiler _render_in_expr_w_bindparam method for an # IN expression self.expand_op = None self.literal_execute = literal_execute if _is_crud: self._is_crud = True if type_ is None: if expanding: if value: check_value = value[0] else: check_value = type_api._NO_VALUE_IN_LIST else: check_value = value if _compared_to_type is not None: self.type = _compared_to_type.coerce_compared_value( _compared_to_operator, check_value ) else: self.type = type_api._resolve_value_to_type(check_value) elif isinstance(type_, type): self.type = type_() elif is_tuple_type(type_): if value: if expanding: check_value = value[0] else: check_value = value cast("BindParameter[typing_Tuple[Any, ...]]", self).type = ( type_._resolve_values_to_types(check_value) ) else: cast("BindParameter[typing_Tuple[Any, ...]]", self).type = ( type_ ) else: self.type = type_ def _with_value(self, value, maintain_key=False, required=NO_ARG): """Return a copy of this :class:`.BindParameter` with the given value set. """ cloned = self._clone(maintain_key=maintain_key) cloned.value = value cloned.callable = None cloned.required = required if required is not NO_ARG else self.required if cloned.type is type_api.NULLTYPE: cloned.type = type_api._resolve_value_to_type(value) return cloned @property def effective_value(self) -> Optional[_T]: """Return the value of this bound parameter, taking into account if the ``callable`` parameter was set. The ``callable`` value will be evaluated and returned if present, else ``value``. """ if self.callable: # TODO: set up protocol for bind parameter callable return self.callable() # type: ignore else: return self.value def render_literal_execute(self) -> BindParameter[_T]: """Produce a copy of this bound parameter that will enable the :paramref:`_sql.BindParameter.literal_execute` flag. The :paramref:`_sql.BindParameter.literal_execute` flag will have the effect of the parameter rendered in the compiled SQL string using ``[POSTCOMPILE]`` form, which is a special form that is converted to be a rendering of the literal value of the parameter at SQL execution time. The rationale is to support caching of SQL statement strings that can embed per-statement literal values, such as LIMIT and OFFSET parameters, in the final SQL string that is passed to the DBAPI. Dialects in particular may want to use this method within custom compilation schemes. .. versionadded:: 1.4.5 .. seealso:: :ref:`engine_thirdparty_caching` """ c = ClauseElement._clone(self) c.literal_execute = True return c def _negate_in_binary(self, negated_op, original_op): if self.expand_op is original_op: bind = self._clone() bind.expand_op = negated_op return bind else: return self def _with_binary_element_type(self, type_): c = ClauseElement._clone(self) c.type = type_ return c def _clone(self, maintain_key: bool = False, **kw: Any) -> Self: c = ClauseElement._clone(self, **kw) # ensure all the BindParameter objects stay in cloned set. # in #7823, we changed "clone" so that a clone only keeps a reference # to the "original" element, since for column correspondence, that's # all we need. However, for BindParam, _cloned_set is used by # the "cache key bind match" lookup, which means if any of those # interim BindParameter objects became part of a cache key in the # cache, we need it. So here, make sure all clones keep carrying # forward. c._cloned_set.update(self._cloned_set) if not maintain_key and self.unique: c.key = _anonymous_label.safe_construct( id(c), c._orig_key or "param", sanitize_key=True ) return c def _gen_cache_key(self, anon_map, bindparams): _gen_cache_ok = self.__class__.__dict__.get("inherit_cache", False) if not _gen_cache_ok: if anon_map is not None: anon_map[NO_CACHE] = True return None id_, found = anon_map.get_anon(self) if found: return (id_, self.__class__) if bindparams is not None: bindparams.append(self) return ( id_, self.__class__, self.type._static_cache_key, self.key % anon_map if self._key_is_anon else self.key, self.literal_execute, ) def _convert_to_unique(self): if not self.unique: self.unique = True self.key = _anonymous_label.safe_construct( id(self), self._orig_key or "param", sanitize_key=True ) def __getstate__(self): """execute a deferred value for serialization purposes.""" d = self.__dict__.copy() v = self.value if self.callable: v = self.callable() d["callable"] = None d["value"] = v return d def __setstate__(self, state): if state.get("unique", False): state["key"] = _anonymous_label.safe_construct( id(self), state.get("_orig_key", "param"), sanitize_key=True ) self.__dict__.update(state) def __repr__(self): return "%s(%r, %r, type_=%r)" % ( self.__class__.__name__, self.key, self.value, self.type, ) class TypeClause(DQLDMLClauseElement): """Handle a type keyword in a SQL statement. Used by the ``Case`` statement. """ __visit_name__ = "typeclause" _traverse_internals: _TraverseInternalsType = [ ("type", InternalTraversal.dp_type) ] def __init__(self, type_): self.type = type_ class TextClause( roles.DDLConstraintColumnRole, roles.DDLExpressionRole, roles.StatementOptionRole, roles.WhereHavingRole, roles.OrderByRole, roles.FromClauseRole, roles.SelectStatementRole, roles.InElementRole, Generative, Executable, DQLDMLClauseElement, roles.BinaryElementRole[Any], inspection.Inspectable["TextClause"], ): """Represent a literal SQL text fragment. E.g.:: from sqlalchemy import text t = text("SELECT * FROM users") result = connection.execute(t) The :class:`_expression.TextClause` construct is produced using the :func:`_expression.text` function; see that function for full documentation. .. seealso:: :func:`_expression.text` """ __visit_name__ = "textclause" _traverse_internals: _TraverseInternalsType = [ ("_bindparams", InternalTraversal.dp_string_clauseelement_dict), ("text", InternalTraversal.dp_string), ] _is_text_clause = True _is_textual = True _bind_params_regex = re.compile(r"(?<![:\w\x5c]):(\w+)(?!:)", re.UNICODE) _is_implicitly_boolean = False _render_label_in_columns_clause = False _omit_from_statements = False _is_collection_aggregate = False @property def _hide_froms(self) -> Iterable[FromClause]: return () def __and__(self, other): # support use in select.where(), query.filter() return and_(self, other) @property def _select_iterable(self) -> _SelectIterable: return (self,) # help in those cases where text() is # interpreted in a column expression situation key: Optional[str] = None _label: Optional[str] = None _allow_label_resolve = False @property def _is_star(self): return self.text == "*" def __init__(self, text: str): self._bindparams: Dict[str, BindParameter[Any]] = {} def repl(m): self._bindparams[m.group(1)] = BindParameter(m.group(1)) return ":%s" % m.group(1) # scan the string and search for bind parameter names, add them # to the list of bindparams self.text = self._bind_params_regex.sub(repl, text) @_generative def bindparams( self, *binds: BindParameter[Any], **names_to_values: Any, ) -> Self: """Establish the values and/or types of bound parameters within this :class:`_expression.TextClause` construct. Given a text construct such as:: from sqlalchemy import text stmt = text("SELECT id, name FROM user WHERE name=:name " "AND timestamp=:timestamp") the :meth:`_expression.TextClause.bindparams` method can be used to establish the initial value of ``:name`` and ``:timestamp``, using simple keyword arguments:: stmt = stmt.bindparams(name='jack', timestamp=datetime.datetime(2012, 10, 8, 15, 12, 5)) Where above, new :class:`.BindParameter` objects will be generated with the names ``name`` and ``timestamp``, and values of ``jack`` and ``datetime.datetime(2012, 10, 8, 15, 12, 5)``, respectively. The types will be inferred from the values given, in this case :class:`.String` and :class:`.DateTime`. When specific typing behavior is needed, the positional ``*binds`` argument can be used in which to specify :func:`.bindparam` constructs directly. These constructs must include at least the ``key`` argument, then an optional value and type:: from sqlalchemy import bindparam stmt = stmt.bindparams( bindparam('name', value='jack', type_=String), bindparam('timestamp', type_=DateTime) ) Above, we specified the type of :class:`.DateTime` for the ``timestamp`` bind, and the type of :class:`.String` for the ``name`` bind. In the case of ``name`` we also set the default value of ``"jack"``. Additional bound parameters can be supplied at statement execution time, e.g.:: result = connection.execute(stmt, timestamp=datetime.datetime(2012, 10, 8, 15, 12, 5)) The :meth:`_expression.TextClause.bindparams` method can be called repeatedly, where it will re-use existing :class:`.BindParameter` objects to add new information. For example, we can call :meth:`_expression.TextClause.bindparams` first with typing information, and a second time with value information, and it will be combined:: stmt = text("SELECT id, name FROM user WHERE name=:name " "AND timestamp=:timestamp") stmt = stmt.bindparams( bindparam('name', type_=String), bindparam('timestamp', type_=DateTime) ) stmt = stmt.bindparams( name='jack', timestamp=datetime.datetime(2012, 10, 8, 15, 12, 5) ) The :meth:`_expression.TextClause.bindparams` method also supports the concept of **unique** bound parameters. These are parameters that are "uniquified" on name at statement compilation time, so that multiple :func:`_expression.text` constructs may be combined together without the names conflicting. To use this feature, specify the :paramref:`.BindParameter.unique` flag on each :func:`.bindparam` object:: stmt1 = text("select id from table where name=:name").bindparams( bindparam("name", value='name1', unique=True) ) stmt2 = text("select id from table where name=:name").bindparams( bindparam("name", value='name2', unique=True) ) union = union_all( stmt1.columns(column("id")), stmt2.columns(column("id")) ) The above statement will render as:: select id from table where name=:name_1 UNION ALL select id from table where name=:name_2 .. versionadded:: 1.3.11 Added support for the :paramref:`.BindParameter.unique` flag to work with :func:`_expression.text` constructs. """ self._bindparams = new_params = self._bindparams.copy() for bind in binds: try: # the regex used for text() currently will not match # a unique/anonymous key in any case, so use the _orig_key # so that a text() construct can support unique parameters existing = new_params[bind._orig_key] except KeyError as err: raise exc.ArgumentError( "This text() construct doesn't define a " "bound parameter named %r" % bind._orig_key ) from err else: new_params[existing._orig_key] = bind for key, value in names_to_values.items(): try: existing = new_params[key] except KeyError as err: raise exc.ArgumentError( "This text() construct doesn't define a " "bound parameter named %r" % key ) from err else: new_params[key] = existing._with_value(value, required=False) return self @util.preload_module("sqlalchemy.sql.selectable") def columns( self, *cols: _ColumnExpressionArgument[Any], **types: TypeEngine[Any] ) -> TextualSelect: r"""Turn this :class:`_expression.TextClause` object into a :class:`_expression.TextualSelect` object that serves the same role as a SELECT statement. The :class:`_expression.TextualSelect` is part of the :class:`_expression.SelectBase` hierarchy and can be embedded into another statement by using the :meth:`_expression.TextualSelect.subquery` method to produce a :class:`.Subquery` object, which can then be SELECTed from. This function essentially bridges the gap between an entirely textual SELECT statement and the SQL expression language concept of a "selectable":: from sqlalchemy.sql import column, text stmt = text("SELECT id, name FROM some_table") stmt = stmt.columns(column('id'), column('name')).subquery('st') stmt = select(mytable).\ select_from( mytable.join(stmt, mytable.c.name == stmt.c.name) ).where(stmt.c.id > 5) Above, we pass a series of :func:`_expression.column` elements to the :meth:`_expression.TextClause.columns` method positionally. These :func:`_expression.column` elements now become first class elements upon the :attr:`_expression.TextualSelect.selected_columns` column collection, which then become part of the :attr:`.Subquery.c` collection after :meth:`_expression.TextualSelect.subquery` is invoked. The column expressions we pass to :meth:`_expression.TextClause.columns` may also be typed; when we do so, these :class:`.TypeEngine` objects become the effective return type of the column, so that SQLAlchemy's result-set-processing systems may be used on the return values. This is often needed for types such as date or boolean types, as well as for unicode processing on some dialect configurations:: stmt = text("SELECT id, name, timestamp FROM some_table") stmt = stmt.columns( column('id', Integer), column('name', Unicode), column('timestamp', DateTime) ) for id, name, timestamp in connection.execute(stmt): print(id, name, timestamp) As a shortcut to the above syntax, keyword arguments referring to types alone may be used, if only type conversion is needed:: stmt = text("SELECT id, name, timestamp FROM some_table") stmt = stmt.columns( id=Integer, name=Unicode, timestamp=DateTime ) for id, name, timestamp in connection.execute(stmt): print(id, name, timestamp) The positional form of :meth:`_expression.TextClause.columns` also provides the unique feature of **positional column targeting**, which is particularly useful when using the ORM with complex textual queries. If we specify the columns from our model to :meth:`_expression.TextClause.columns`, the result set will match to those columns positionally, meaning the name or origin of the column in the textual SQL doesn't matter:: stmt = text("SELECT users.id, addresses.id, users.id, " "users.name, addresses.email_address AS email " "FROM users JOIN addresses ON users.id=addresses.user_id " "WHERE users.id = 1").columns( User.id, Address.id, Address.user_id, User.name, Address.email_address ) query = session.query(User).from_statement(stmt).options( contains_eager(User.addresses)) The :meth:`_expression.TextClause.columns` method provides a direct route to calling :meth:`_expression.FromClause.subquery` as well as :meth:`_expression.SelectBase.cte` against a textual SELECT statement:: stmt = stmt.columns(id=Integer, name=String).cte('st') stmt = select(sometable).where(sometable.c.id == stmt.c.id) :param \*cols: A series of :class:`_expression.ColumnElement` objects, typically :class:`_schema.Column` objects from a :class:`_schema.Table` or ORM level column-mapped attributes, representing a set of columns that this textual string will SELECT from. :param \**types: A mapping of string names to :class:`.TypeEngine` type objects indicating the datatypes to use for names that are SELECTed from the textual string. Prefer to use the ``*cols`` argument as it also indicates positional ordering. """ selectable = util.preloaded.sql_selectable input_cols: List[NamedColumn[Any]] = [ coercions.expect(roles.LabeledColumnExprRole, col) for col in cols ] positional_input_cols = [ ( ColumnClause(col.key, types.pop(col.key)) if col.key in types else col ) for col in input_cols ] keyed_input_cols: List[NamedColumn[Any]] = [ ColumnClause(key, type_) for key, type_ in types.items() ] elem = selectable.TextualSelect.__new__(selectable.TextualSelect) elem._init( self, positional_input_cols + keyed_input_cols, positional=bool(positional_input_cols) and not keyed_input_cols, ) return elem @property def type(self) -> TypeEngine[Any]: return type_api.NULLTYPE @property def comparator(self): # TODO: this seems wrong, it seems like we might not # be using this method. return self.type.comparator_factory(self) # type: ignore def self_group( self, against: Optional[OperatorType] = None ) -> Union[Self, Grouping[Any]]: if against is operators.in_op: return Grouping(self) else: return self class Null(SingletonConstant, roles.ConstExprRole[None], ColumnElement[None]): """Represent the NULL keyword in a SQL statement. :class:`.Null` is accessed as a constant via the :func:`.null` function. """ __visit_name__ = "null" _traverse_internals: _TraverseInternalsType = [] _singleton: Null if not TYPE_CHECKING: @util.memoized_property def type(self) -> TypeEngine[_T]: # noqa: A001 return type_api.NULLTYPE @classmethod def _instance(cls) -> Null: """Return a constant :class:`.Null` construct.""" return Null._singleton Null._create_singleton() class False_( SingletonConstant, roles.ConstExprRole[bool], ColumnElement[bool] ): """Represent the ``false`` keyword, or equivalent, in a SQL statement. :class:`.False_` is accessed as a constant via the :func:`.false` function. """ __visit_name__ = "false" _traverse_internals: _TraverseInternalsType = [] _singleton: False_ if not TYPE_CHECKING: @util.memoized_property def type(self) -> TypeEngine[_T]: # noqa: A001 return type_api.BOOLEANTYPE def _negate(self) -> True_: return True_._singleton @classmethod def _instance(cls) -> False_: return False_._singleton False_._create_singleton() class True_(SingletonConstant, roles.ConstExprRole[bool], ColumnElement[bool]): """Represent the ``true`` keyword, or equivalent, in a SQL statement. :class:`.True_` is accessed as a constant via the :func:`.true` function. """ __visit_name__ = "true" _traverse_internals: _TraverseInternalsType = [] _singleton: True_ if not TYPE_CHECKING: @util.memoized_property def type(self) -> TypeEngine[_T]: # noqa: A001 return type_api.BOOLEANTYPE def _negate(self) -> False_: return False_._singleton @classmethod def _ifnone( cls, other: Optional[ColumnElement[Any]] ) -> ColumnElement[Any]: if other is None: return cls._instance() else: return other @classmethod def _instance(cls) -> True_: return True_._singleton True_._create_singleton() class ClauseList( roles.InElementRole, roles.OrderByRole, roles.ColumnsClauseRole, roles.DMLColumnRole, DQLDMLClauseElement, ): """Describe a list of clauses, separated by an operator. By default, is comma-separated, such as a column listing. """ __visit_name__ = "clauselist" # this is used only by the ORM in a legacy use case for # composite attributes _is_clause_list = True _traverse_internals: _TraverseInternalsType = [ ("clauses", InternalTraversal.dp_clauseelement_list), ("operator", InternalTraversal.dp_operator), ] clauses: List[ColumnElement[Any]] def __init__( self, *clauses: _ColumnExpressionArgument[Any], operator: OperatorType = operators.comma_op, group: bool = True, group_contents: bool = True, _literal_as_text_role: Type[roles.SQLRole] = roles.WhereHavingRole, ): self.operator = operator self.group = group self.group_contents = group_contents clauses_iterator: Iterable[_ColumnExpressionArgument[Any]] = clauses text_converter_role: Type[roles.SQLRole] = _literal_as_text_role self._text_converter_role = text_converter_role if self.group_contents: self.clauses = [ coercions.expect( text_converter_role, clause, apply_propagate_attrs=self ).self_group(against=self.operator) for clause in clauses_iterator ] else: self.clauses = [ coercions.expect( text_converter_role, clause, apply_propagate_attrs=self ) for clause in clauses_iterator ] self._is_implicitly_boolean = operators.is_boolean(self.operator) @classmethod def _construct_raw( cls, operator: OperatorType, clauses: Optional[Sequence[ColumnElement[Any]]] = None, ) -> ClauseList: self = cls.__new__(cls) self.clauses = list(clauses) if clauses else [] self.group = True self.operator = operator self.group_contents = True self._is_implicitly_boolean = False return self def __iter__(self) -> Iterator[ColumnElement[Any]]: return iter(self.clauses) def __len__(self) -> int: return len(self.clauses) @property def _select_iterable(self) -> _SelectIterable: return itertools.chain.from_iterable( [elem._select_iterable for elem in self.clauses] ) def append(self, clause): if self.group_contents: self.clauses.append( coercions.expect(self._text_converter_role, clause).self_group( against=self.operator ) ) else: self.clauses.append( coercions.expect(self._text_converter_role, clause) ) @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return list(itertools.chain(*[c._from_objects for c in self.clauses])) def self_group( self, against: Optional[OperatorType] = None ) -> Union[Self, Grouping[Any]]: if self.group and operators.is_precedent(self.operator, against): return Grouping(self) else: return self class OperatorExpression(ColumnElement[_T]): """base for expressions that contain an operator and operands .. versionadded:: 2.0 """ operator: OperatorType type: TypeEngine[_T] group: bool = True @property def is_comparison(self): return operators.is_comparison(self.operator) def self_group( self, against: Optional[OperatorType] = None ) -> Union[Self, Grouping[_T]]: if ( self.group and operators.is_precedent(self.operator, against) or ( # a negate against a non-boolean operator # doesn't make too much sense but we should # group for that against is operators.inv and not operators.is_boolean(self.operator) ) ): return Grouping(self) else: return self @property def _flattened_operator_clauses( self, ) -> typing_Tuple[ColumnElement[Any], ...]: raise NotImplementedError() @classmethod def _construct_for_op( cls, left: ColumnElement[Any], right: ColumnElement[Any], op: OperatorType, *, type_: TypeEngine[_T], negate: Optional[OperatorType] = None, modifiers: Optional[Mapping[str, Any]] = None, ) -> OperatorExpression[_T]: if operators.is_associative(op): assert ( negate is None ), f"negate not supported for associative operator {op}" multi = False if getattr( left, "operator", None ) is op and type_._compare_type_affinity(left.type): multi = True left_flattened = left._flattened_operator_clauses else: left_flattened = (left,) if getattr( right, "operator", None ) is op and type_._compare_type_affinity(right.type): multi = True right_flattened = right._flattened_operator_clauses else: right_flattened = (right,) if multi: return ExpressionClauseList._construct_for_list( op, type_, *(left_flattened + right_flattened), ) if right._is_collection_aggregate: negate = None return BinaryExpression( left, right, op, type_=type_, negate=negate, modifiers=modifiers ) class ExpressionClauseList(OperatorExpression[_T]): """Describe a list of clauses, separated by an operator, in a column expression context. :class:`.ExpressionClauseList` differs from :class:`.ClauseList` in that it represents a column-oriented DQL expression only, not an open ended list of anything comma separated. .. versionadded:: 2.0 """ __visit_name__ = "expression_clauselist" _traverse_internals: _TraverseInternalsType = [ ("clauses", InternalTraversal.dp_clauseelement_tuple), ("operator", InternalTraversal.dp_operator), ] clauses: typing_Tuple[ColumnElement[Any], ...] group: bool def __init__( self, operator: OperatorType, *clauses: _ColumnExpressionArgument[Any], type_: Optional[_TypeEngineArgument[_T]] = None, ): self.operator = operator self.clauses = tuple( coercions.expect( roles.ExpressionElementRole, clause, apply_propagate_attrs=self ) for clause in clauses ) self._is_implicitly_boolean = operators.is_boolean(self.operator) self.type = type_api.to_instance(type_) # type: ignore @property def _flattened_operator_clauses( self, ) -> typing_Tuple[ColumnElement[Any], ...]: return self.clauses def __iter__(self) -> Iterator[ColumnElement[Any]]: return iter(self.clauses) def __len__(self) -> int: return len(self.clauses) @property def _select_iterable(self) -> _SelectIterable: return (self,) @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return list(itertools.chain(*[c._from_objects for c in self.clauses])) def _append_inplace(self, clause: ColumnElement[Any]) -> None: self.clauses += (clause,) @classmethod def _construct_for_list( cls, operator: OperatorType, type_: TypeEngine[_T], *clauses: ColumnElement[Any], group: bool = True, ) -> ExpressionClauseList[_T]: self = cls.__new__(cls) self.group = group if group: self.clauses = tuple( c.self_group(against=operator) for c in clauses ) else: self.clauses = clauses self.operator = operator self.type = type_ return self def _negate(self) -> Any: grouped = self.self_group(against=operators.inv) assert isinstance(grouped, ColumnElement) return UnaryExpression( grouped, operator=operators.inv, wraps_column_expression=True ) class BooleanClauseList(ExpressionClauseList[bool]): __visit_name__ = "expression_clauselist" inherit_cache = True def __init__(self, *arg, **kw): raise NotImplementedError( "BooleanClauseList has a private constructor" ) @classmethod def _process_clauses_for_boolean( cls, operator: OperatorType, continue_on: Any, skip_on: Any, clauses: Iterable[ColumnElement[Any]], ) -> typing_Tuple[int, List[ColumnElement[Any]]]: has_continue_on = None convert_clauses = [] against = operators._asbool lcc = 0 for clause in clauses: if clause is continue_on: # instance of continue_on, like and_(x, y, True, z), store it # if we didn't find one already, we will use it if there # are no other expressions here. has_continue_on = clause elif clause is skip_on: # instance of skip_on, e.g. and_(x, y, False, z), cancels # the rest out convert_clauses = [clause] lcc = 1 break else: if not lcc: lcc = 1 else: against = operator # technically this would be len(convert_clauses) + 1 # however this only needs to indicate "greater than one" lcc = 2 convert_clauses.append(clause) if not convert_clauses and has_continue_on is not None: convert_clauses = [has_continue_on] lcc = 1 return lcc, [c.self_group(against=against) for c in convert_clauses] @classmethod def _construct( cls, operator: OperatorType, continue_on: Any, skip_on: Any, initial_clause: Any = _NoArg.NO_ARG, *clauses: Any, **kw: Any, ) -> ColumnElement[Any]: if initial_clause is _NoArg.NO_ARG: # no elements period. deprecated use case. return an empty # ClauseList construct that generates nothing unless it has # elements added to it. name = operator.__name__ util.warn_deprecated( f"Invoking {name}() without arguments is deprecated, and " f"will be disallowed in a future release. For an empty " f"""{name}() construct, use '{name}({ 'true()' if continue_on is True_._singleton else 'false()' }, *args)' """ f"""or '{name}({ 'True' if continue_on is True_._singleton else 'False' }, *args)'.""", version="1.4", ) return cls._construct_raw(operator) lcc, convert_clauses = cls._process_clauses_for_boolean( operator, continue_on, skip_on, [ coercions.expect(roles.WhereHavingRole, clause) for clause in util.coerce_generator_arg( (initial_clause,) + clauses ) ], ) if lcc > 1: # multiple elements. Return regular BooleanClauseList # which will link elements against the operator. flattened_clauses = itertools.chain.from_iterable( ( (c for c in to_flat._flattened_operator_clauses) if getattr(to_flat, "operator", None) is operator else (to_flat,) ) for to_flat in convert_clauses ) return cls._construct_raw(operator, flattened_clauses) # type: ignore # noqa: E501 else: assert lcc # just one element. return it as a single boolean element, # not a list and discard the operator. return convert_clauses[0] @classmethod def _construct_for_whereclause( cls, clauses: Iterable[ColumnElement[Any]] ) -> Optional[ColumnElement[bool]]: operator, continue_on, skip_on = ( operators.and_, True_._singleton, False_._singleton, ) lcc, convert_clauses = cls._process_clauses_for_boolean( operator, continue_on, skip_on, clauses, # these are assumed to be coerced already ) if lcc > 1: # multiple elements. Return regular BooleanClauseList # which will link elements against the operator. return cls._construct_raw(operator, convert_clauses) elif lcc == 1: # just one element. return it as a single boolean element, # not a list and discard the operator. return convert_clauses[0] else: return None @classmethod def _construct_raw( cls, operator: OperatorType, clauses: Optional[Sequence[ColumnElement[Any]]] = None, ) -> BooleanClauseList: self = cls.__new__(cls) self.clauses = tuple(clauses) if clauses else () self.group = True self.operator = operator self.type = type_api.BOOLEANTYPE self._is_implicitly_boolean = True return self @classmethod def and_( cls, initial_clause: Union[ Literal[True], _ColumnExpressionArgument[bool], _NoArg ] = _NoArg.NO_ARG, *clauses: _ColumnExpressionArgument[bool], ) -> ColumnElement[bool]: r"""Produce a conjunction of expressions joined by ``AND``. See :func:`_sql.and_` for full documentation. """ return cls._construct( operators.and_, True_._singleton, False_._singleton, initial_clause, *clauses, ) @classmethod def or_( cls, initial_clause: Union[ Literal[False], _ColumnExpressionArgument[bool], _NoArg ] = _NoArg.NO_ARG, *clauses: _ColumnExpressionArgument[bool], ) -> ColumnElement[bool]: """Produce a conjunction of expressions joined by ``OR``. See :func:`_sql.or_` for full documentation. """ return cls._construct( operators.or_, False_._singleton, True_._singleton, initial_clause, *clauses, ) @property def _select_iterable(self) -> _SelectIterable: return (self,) def self_group( self, against: Optional[OperatorType] = None ) -> Union[Self, Grouping[bool]]: if not self.clauses: return self else: return super().self_group(against=against) and_ = BooleanClauseList.and_ or_ = BooleanClauseList.or_ class Tuple(ClauseList, ColumnElement[typing_Tuple[Any, ...]]): """Represent a SQL tuple.""" __visit_name__ = "tuple" _traverse_internals: _TraverseInternalsType = ( ClauseList._traverse_internals + [] ) type: TupleType @util.preload_module("sqlalchemy.sql.sqltypes") def __init__( self, *clauses: _ColumnExpressionArgument[Any], types: Optional[Sequence[_TypeEngineArgument[Any]]] = None, ): sqltypes = util.preloaded.sql_sqltypes if types is None: init_clauses: List[ColumnElement[Any]] = [ coercions.expect(roles.ExpressionElementRole, c) for c in clauses ] else: if len(types) != len(clauses): raise exc.ArgumentError( "Wrong number of elements for %d-tuple: %r " % (len(types), clauses) ) init_clauses = [ coercions.expect( roles.ExpressionElementRole, c, type_=typ if not typ._isnull else None, ) for typ, c in zip(types, clauses) ] self.type = sqltypes.TupleType(*[arg.type for arg in init_clauses]) super().__init__(*init_clauses) @property def _select_iterable(self) -> _SelectIterable: return (self,) def _bind_param(self, operator, obj, type_=None, expanding=False): if expanding: return BindParameter( None, value=obj, _compared_to_operator=operator, unique=True, expanding=True, type_=type_, _compared_to_type=self.type, ) else: return Tuple( *[ BindParameter( None, o, _compared_to_operator=operator, _compared_to_type=compared_to_type, unique=True, type_=type_, ) for o, compared_to_type in zip(obj, self.type.types) ] ) def self_group(self, against: Optional[OperatorType] = None) -> Self: # Tuple is parenthesized by definition. return self class Case(ColumnElement[_T]): """Represent a ``CASE`` expression. :class:`.Case` is produced using the :func:`.case` factory function, as in:: from sqlalchemy import case stmt = select(users_table).\ where( case( (users_table.c.name == 'wendy', 'W'), (users_table.c.name == 'jack', 'J'), else_='E' ) ) Details on :class:`.Case` usage is at :func:`.case`. .. seealso:: :func:`.case` """ __visit_name__ = "case" _traverse_internals: _TraverseInternalsType = [ ("value", InternalTraversal.dp_clauseelement), ("whens", InternalTraversal.dp_clauseelement_tuples), ("else_", InternalTraversal.dp_clauseelement), ] # for case(), the type is derived from the whens. so for the moment # users would have to cast() the case to get a specific type whens: List[typing_Tuple[ColumnElement[bool], ColumnElement[_T]]] else_: Optional[ColumnElement[_T]] value: Optional[ColumnElement[Any]] def __init__( self, *whens: Union[ typing_Tuple[_ColumnExpressionArgument[bool], Any], Mapping[Any, Any], ], value: Optional[Any] = None, else_: Optional[Any] = None, ): new_whens: Iterable[Any] = coercions._expression_collection_was_a_list( "whens", "case", whens ) try: new_whens = util.dictlike_iteritems(new_whens) except TypeError: pass self.whens = [ ( coercions.expect( roles.ExpressionElementRole, c, apply_propagate_attrs=self, ).self_group(), coercions.expect(roles.ExpressionElementRole, r), ) for (c, r) in new_whens ] if value is None: self.value = None else: self.value = coercions.expect(roles.ExpressionElementRole, value) if else_ is not None: self.else_ = coercions.expect(roles.ExpressionElementRole, else_) else: self.else_ = None type_ = next( ( then.type # Iterate `whens` in reverse to match previous behaviour # where type of final element took priority for *_, then in reversed(self.whens) if not then.type._isnull ), self.else_.type if self.else_ is not None else type_api.NULLTYPE, ) self.type = cast(_T, type_) @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return list( itertools.chain(*[x._from_objects for x in self.get_children()]) ) class Cast(WrapsColumnExpression[_T]): """Represent a ``CAST`` expression. :class:`.Cast` is produced using the :func:`.cast` factory function, as in:: from sqlalchemy import cast, Numeric stmt = select(cast(product_table.c.unit_price, Numeric(10, 4))) Details on :class:`.Cast` usage is at :func:`.cast`. .. seealso:: :ref:`tutorial_casts` :func:`.cast` :func:`.try_cast` :func:`.type_coerce` - an alternative to CAST that coerces the type on the Python side only, which is often sufficient to generate the correct SQL and data coercion. """ __visit_name__ = "cast" _traverse_internals: _TraverseInternalsType = [ ("clause", InternalTraversal.dp_clauseelement), ("type", InternalTraversal.dp_type), ] clause: ColumnElement[Any] type: TypeEngine[_T] typeclause: TypeClause def __init__( self, expression: _ColumnExpressionArgument[Any], type_: _TypeEngineArgument[_T], ): self.type = type_api.to_instance(type_) self.clause = coercions.expect( roles.ExpressionElementRole, expression, type_=self.type, apply_propagate_attrs=self, ) self.typeclause = TypeClause(self.type) @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return self.clause._from_objects @property def wrapped_column_expression(self): return self.clause class TryCast(Cast[_T]): """Represent a TRY_CAST expression. Details on :class:`.TryCast` usage is at :func:`.try_cast`. .. seealso:: :func:`.try_cast` :ref:`tutorial_casts` """ __visit_name__ = "try_cast" inherit_cache = True class TypeCoerce(WrapsColumnExpression[_T]): """Represent a Python-side type-coercion wrapper. :class:`.TypeCoerce` supplies the :func:`_expression.type_coerce` function; see that function for usage details. .. seealso:: :func:`_expression.type_coerce` :func:`.cast` """ __visit_name__ = "type_coerce" _traverse_internals: _TraverseInternalsType = [ ("clause", InternalTraversal.dp_clauseelement), ("type", InternalTraversal.dp_type), ] clause: ColumnElement[Any] type: TypeEngine[_T] def __init__( self, expression: _ColumnExpressionArgument[Any], type_: _TypeEngineArgument[_T], ): self.type = type_api.to_instance(type_) self.clause = coercions.expect( roles.ExpressionElementRole, expression, type_=self.type, apply_propagate_attrs=self, ) @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return self.clause._from_objects @HasMemoized.memoized_attribute def typed_expression(self): if isinstance(self.clause, BindParameter): bp = self.clause._clone() bp.type = self.type return bp else: return self.clause @property def wrapped_column_expression(self): return self.clause def self_group( self, against: Optional[OperatorType] = None ) -> TypeCoerce[_T]: grouped = self.clause.self_group(against=against) if grouped is not self.clause: return TypeCoerce(grouped, self.type) else: return self class Extract(ColumnElement[int]): """Represent a SQL EXTRACT clause, ``extract(field FROM expr)``.""" __visit_name__ = "extract" _traverse_internals: _TraverseInternalsType = [ ("expr", InternalTraversal.dp_clauseelement), ("field", InternalTraversal.dp_string), ] expr: ColumnElement[Any] field: str def __init__(self, field: str, expr: _ColumnExpressionArgument[Any]): self.type = type_api.INTEGERTYPE self.field = field self.expr = coercions.expect(roles.ExpressionElementRole, expr) @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return self.expr._from_objects class _label_reference(ColumnElement[_T]): """Wrap a column expression as it appears in a 'reference' context. This expression is any that includes an _order_by_label_element, which is a Label, or a DESC / ASC construct wrapping a Label. The production of _label_reference() should occur when an expression is added to this context; this includes the ORDER BY or GROUP BY of a SELECT statement, as well as a few other places, such as the ORDER BY within an OVER clause. """ __visit_name__ = "label_reference" _traverse_internals: _TraverseInternalsType = [ ("element", InternalTraversal.dp_clauseelement) ] element: ColumnElement[_T] def __init__(self, element: ColumnElement[_T]): self.element = element @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return [] class _textual_label_reference(ColumnElement[Any]): __visit_name__ = "textual_label_reference" _traverse_internals: _TraverseInternalsType = [ ("element", InternalTraversal.dp_string) ] def __init__(self, element: str): self.element = element @util.memoized_property def _text_clause(self) -> TextClause: return TextClause(self.element) class UnaryExpression(ColumnElement[_T]): """Define a 'unary' expression. A unary expression has a single column expression and an operator. The operator can be placed on the left (where it is called the 'operator') or right (where it is called the 'modifier') of the column expression. :class:`.UnaryExpression` is the basis for several unary operators including those used by :func:`.desc`, :func:`.asc`, :func:`.distinct`, :func:`.nulls_first` and :func:`.nulls_last`. """ __visit_name__ = "unary" _traverse_internals: _TraverseInternalsType = [ ("element", InternalTraversal.dp_clauseelement), ("operator", InternalTraversal.dp_operator), ("modifier", InternalTraversal.dp_operator), ] element: ClauseElement def __init__( self, element: ColumnElement[Any], operator: Optional[OperatorType] = None, modifier: Optional[OperatorType] = None, type_: Optional[_TypeEngineArgument[_T]] = None, wraps_column_expression: bool = False, ): self.operator = operator self.modifier = modifier self._propagate_attrs = element._propagate_attrs self.element = element.self_group( against=self.operator or self.modifier ) # if type is None, we get NULLTYPE, which is our _T. But I don't # know how to get the overloads to express that correctly self.type = type_api.to_instance(type_) # type: ignore self.wraps_column_expression = wraps_column_expression @classmethod def _create_nulls_first( cls, column: _ColumnExpressionArgument[_T], ) -> UnaryExpression[_T]: return UnaryExpression( coercions.expect(roles.ByOfRole, column), modifier=operators.nulls_first_op, wraps_column_expression=False, ) @classmethod def _create_nulls_last( cls, column: _ColumnExpressionArgument[_T], ) -> UnaryExpression[_T]: return UnaryExpression( coercions.expect(roles.ByOfRole, column), modifier=operators.nulls_last_op, wraps_column_expression=False, ) @classmethod def _create_desc( cls, column: _ColumnExpressionOrStrLabelArgument[_T] ) -> UnaryExpression[_T]: return UnaryExpression( coercions.expect(roles.ByOfRole, column), modifier=operators.desc_op, wraps_column_expression=False, ) @classmethod def _create_asc( cls, column: _ColumnExpressionOrStrLabelArgument[_T], ) -> UnaryExpression[_T]: return UnaryExpression( coercions.expect(roles.ByOfRole, column), modifier=operators.asc_op, wraps_column_expression=False, ) @classmethod def _create_distinct( cls, expr: _ColumnExpressionArgument[_T], ) -> UnaryExpression[_T]: col_expr: ColumnElement[_T] = coercions.expect( roles.ExpressionElementRole, expr ) return UnaryExpression( col_expr, operator=operators.distinct_op, type_=col_expr.type, wraps_column_expression=False, ) @classmethod def _create_bitwise_not( cls, expr: _ColumnExpressionArgument[_T], ) -> UnaryExpression[_T]: col_expr: ColumnElement[_T] = coercions.expect( roles.ExpressionElementRole, expr ) return UnaryExpression( col_expr, operator=operators.bitwise_not_op, type_=col_expr.type, wraps_column_expression=False, ) @property def _order_by_label_element(self) -> Optional[Label[Any]]: if operators.is_order_by_modifier(self.modifier): return self.element._order_by_label_element else: return None @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return self.element._from_objects def _negate(self): if self.type._type_affinity is type_api.BOOLEANTYPE._type_affinity: return UnaryExpression( self.self_group(against=operators.inv), operator=operators.inv, type_=type_api.BOOLEANTYPE, wraps_column_expression=self.wraps_column_expression, ) else: return ClauseElement._negate(self) def self_group( self, against: Optional[OperatorType] = None ) -> Union[Self, Grouping[_T]]: if self.operator and operators.is_precedent(self.operator, against): return Grouping(self) else: return self class CollectionAggregate(UnaryExpression[_T]): """Forms the basis for right-hand collection operator modifiers ANY and ALL. The ANY and ALL keywords are available in different ways on different backends. On PostgreSQL, they only work for an ARRAY type. On MySQL, they only work for subqueries. """ inherit_cache = True _is_collection_aggregate = True @classmethod def _create_any( cls, expr: _ColumnExpressionArgument[_T] ) -> CollectionAggregate[bool]: col_expr: ColumnElement[_T] = coercions.expect( roles.ExpressionElementRole, expr, ) col_expr = col_expr.self_group() return CollectionAggregate( col_expr, operator=operators.any_op, type_=type_api.BOOLEANTYPE, wraps_column_expression=False, ) @classmethod def _create_all( cls, expr: _ColumnExpressionArgument[_T] ) -> CollectionAggregate[bool]: col_expr: ColumnElement[_T] = coercions.expect( roles.ExpressionElementRole, expr, ) col_expr = col_expr.self_group() return CollectionAggregate( col_expr, operator=operators.all_op, type_=type_api.BOOLEANTYPE, wraps_column_expression=False, ) # operate and reverse_operate are hardwired to # dispatch onto the type comparator directly, so that we can # ensure "reversed" behavior. def operate(self, op, *other, **kwargs): if not operators.is_comparison(op): raise exc.ArgumentError( "Only comparison operators may be used with ANY/ALL" ) kwargs["reverse"] = True return self.comparator.operate(operators.mirror(op), *other, **kwargs) def reverse_operate(self, op, other, **kwargs): # comparison operators should never call reverse_operate assert not operators.is_comparison(op) raise exc.ArgumentError( "Only comparison operators may be used with ANY/ALL" ) class AsBoolean(WrapsColumnExpression[bool], UnaryExpression[bool]): inherit_cache = True def __init__(self, element, operator, negate): self.element = element self.type = type_api.BOOLEANTYPE self.operator = operator self.negate = negate self.modifier = None self.wraps_column_expression = True self._is_implicitly_boolean = element._is_implicitly_boolean @property def wrapped_column_expression(self): return self.element def self_group(self, against: Optional[OperatorType] = None) -> Self: return self def _negate(self): if isinstance(self.element, (True_, False_)): return self.element._negate() else: return AsBoolean(self.element, self.negate, self.operator) class BinaryExpression(OperatorExpression[_T]): """Represent an expression that is ``LEFT <operator> RIGHT``. A :class:`.BinaryExpression` is generated automatically whenever two column expressions are used in a Python binary expression: .. sourcecode:: pycon+sql >>> from sqlalchemy.sql import column >>> column('a') + column('b') <sqlalchemy.sql.expression.BinaryExpression object at 0x101029dd0> >>> print(column('a') + column('b')) {printsql}a + b """ __visit_name__ = "binary" _traverse_internals: _TraverseInternalsType = [ ("left", InternalTraversal.dp_clauseelement), ("right", InternalTraversal.dp_clauseelement), ("operator", InternalTraversal.dp_operator), ("negate", InternalTraversal.dp_operator), ("modifiers", InternalTraversal.dp_plain_dict), ( "type", InternalTraversal.dp_type, ), ] _cache_key_traversal = [ ("left", InternalTraversal.dp_clauseelement), ("right", InternalTraversal.dp_clauseelement), ("operator", InternalTraversal.dp_operator), ("modifiers", InternalTraversal.dp_plain_dict), # "type" affects JSON CAST operators, so while redundant in most cases, # is needed for that one ( "type", InternalTraversal.dp_type, ), ] _is_implicitly_boolean = True """Indicates that any database will know this is a boolean expression even if the database does not have an explicit boolean datatype. """ modifiers: Optional[Mapping[str, Any]] left: ColumnElement[Any] right: ColumnElement[Any] def __init__( self, left: ColumnElement[Any], right: ColumnElement[Any], operator: OperatorType, type_: Optional[_TypeEngineArgument[_T]] = None, negate: Optional[OperatorType] = None, modifiers: Optional[Mapping[str, Any]] = None, ): # allow compatibility with libraries that # refer to BinaryExpression directly and pass strings if isinstance(operator, str): operator = operators.custom_op(operator) self._orig = (left.__hash__(), right.__hash__()) self._propagate_attrs = left._propagate_attrs or right._propagate_attrs self.left = left.self_group(against=operator) self.right = right.self_group(against=operator) self.operator = operator # if type is None, we get NULLTYPE, which is our _T. But I don't # know how to get the overloads to express that correctly self.type = type_api.to_instance(type_) # type: ignore self.negate = negate self._is_implicitly_boolean = operators.is_boolean(operator) if modifiers is None: self.modifiers = {} else: self.modifiers = modifiers @property def _flattened_operator_clauses( self, ) -> typing_Tuple[ColumnElement[Any], ...]: return (self.left, self.right) def __bool__(self): """Implement Python-side "bool" for BinaryExpression as a simple "identity" check for the left and right attributes, if the operator is "eq" or "ne". Otherwise the expression continues to not support "bool" like all other column expressions. The rationale here is so that ColumnElement objects can be hashable. What? Well, suppose you do this:: c1, c2 = column('x'), column('y') s1 = set([c1, c2]) We do that **a lot**, columns inside of sets is an extremely basic thing all over the ORM for example. So what happens if we do this? :: c1 in s1 Hashing means it will normally use ``__hash__()`` of the object, but in case of hash collision, it's going to also do ``c1 == c1`` and/or ``c1 == c2`` inside. Those operations need to return a True/False value. But because we override ``==`` and ``!=``, they're going to get a BinaryExpression. Hence we implement ``__bool__`` here so that these comparisons behave in this particular context mostly like regular object comparisons. Thankfully Python is OK with that! Otherwise we'd have to use special set classes for columns (which we used to do, decades ago). """ if self.operator in (operators.eq, operators.ne): # this is using the eq/ne operator given int hash values, # rather than Operator, so that "bool" can be based on # identity return self.operator(*self._orig) # type: ignore else: raise TypeError("Boolean value of this clause is not defined") if typing.TYPE_CHECKING: def __invert__( self: BinaryExpression[_T], ) -> BinaryExpression[_T]: ... @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return self.left._from_objects + self.right._from_objects def _negate(self): if self.negate is not None: return BinaryExpression( self.left, self.right._negate_in_binary(self.negate, self.operator), self.negate, negate=self.operator, type_=self.type, modifiers=self.modifiers, ) else: return self.self_group()._negate() class Slice(ColumnElement[Any]): """Represent SQL for a Python array-slice object. This is not a specific SQL construct at this level, but may be interpreted by specific dialects, e.g. PostgreSQL. """ __visit_name__ = "slice" _traverse_internals: _TraverseInternalsType = [ ("start", InternalTraversal.dp_clauseelement), ("stop", InternalTraversal.dp_clauseelement), ("step", InternalTraversal.dp_clauseelement), ] def __init__(self, start, stop, step, _name=None): self.start = coercions.expect( roles.ExpressionElementRole, start, name=_name, type_=type_api.INTEGERTYPE, ) self.stop = coercions.expect( roles.ExpressionElementRole, stop, name=_name, type_=type_api.INTEGERTYPE, ) self.step = coercions.expect( roles.ExpressionElementRole, step, name=_name, type_=type_api.INTEGERTYPE, ) self.type = type_api.NULLTYPE def self_group(self, against: Optional[OperatorType] = None) -> Self: assert against is operator.getitem return self class IndexExpression(BinaryExpression[Any]): """Represent the class of expressions that are like an "index" operation.""" inherit_cache = True class GroupedElement(DQLDMLClauseElement): """Represent any parenthesized expression""" __visit_name__ = "grouping" element: ClauseElement def self_group(self, against: Optional[OperatorType] = None) -> Self: return self def _ungroup(self): return self.element._ungroup() class Grouping(GroupedElement, ColumnElement[_T]): """Represent a grouping within a column expression""" _traverse_internals: _TraverseInternalsType = [ ("element", InternalTraversal.dp_clauseelement), ("type", InternalTraversal.dp_type), ] _cache_key_traversal = [ ("element", InternalTraversal.dp_clauseelement), ] element: Union[TextClause, ClauseList, ColumnElement[_T]] def __init__( self, element: Union[TextClause, ClauseList, ColumnElement[_T]] ): self.element = element # nulltype assignment issue self.type = getattr(element, "type", type_api.NULLTYPE) # type: ignore self._propagate_attrs = element._propagate_attrs def _with_binary_element_type(self, type_): return self.__class__(self.element._with_binary_element_type(type_)) @util.memoized_property def _is_implicitly_boolean(self): return self.element._is_implicitly_boolean @util.non_memoized_property def _tq_label(self) -> Optional[str]: return ( getattr(self.element, "_tq_label", None) or self._anon_name_label ) @util.non_memoized_property def _proxies(self) -> List[ColumnElement[Any]]: if isinstance(self.element, ColumnElement): return [self.element] else: return [] @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return self.element._from_objects def __getattr__(self, attr): return getattr(self.element, attr) def __getstate__(self): return {"element": self.element, "type": self.type} def __setstate__(self, state): self.element = state["element"] self.type = state["type"] if TYPE_CHECKING: def self_group( self, against: Optional[OperatorType] = None ) -> Self: ... class _OverrideBinds(Grouping[_T]): """used by cache_key->_apply_params_to_element to allow compilation / execution of a SQL element that's been cached, using an alternate set of bound parameter values. This is used by the ORM to swap new parameter values into expressions that are embedded into loader options like with_expression(), selectinload(). Previously, this task was accomplished using the .params() method which would perform a deep-copy instead. This deep copy proved to be too expensive for more complex expressions. See #11085 """ __visit_name__ = "override_binds" def __init__( self, element: ColumnElement[_T], bindparams: Sequence[BindParameter[Any]], replaces_params: Sequence[BindParameter[Any]], ): self.element = element self.translate = { k.key: v.value for k, v in zip(replaces_params, bindparams) } def _gen_cache_key( self, anon_map: anon_map, bindparams: List[BindParameter[Any]] ) -> Optional[typing_Tuple[Any, ...]]: """generate a cache key for the given element, substituting its bind values for the translation values present.""" existing_bps: List[BindParameter[Any]] = [] ck = self.element._gen_cache_key(anon_map, existing_bps) bindparams.extend( ( bp._with_value( self.translate[bp.key], maintain_key=True, required=False ) if bp.key in self.translate else bp ) for bp in existing_bps ) return ck class _OverRange(Enum): RANGE_UNBOUNDED = 0 RANGE_CURRENT = 1 RANGE_UNBOUNDED = _OverRange.RANGE_UNBOUNDED RANGE_CURRENT = _OverRange.RANGE_CURRENT _IntOrRange = Union[int, _OverRange] class Over(ColumnElement[_T]): """Represent an OVER clause. This is a special operator against a so-called "window" function, as well as any aggregate function, which produces results relative to the result set itself. Most modern SQL backends now support window functions. """ __visit_name__ = "over" _traverse_internals: _TraverseInternalsType = [ ("element", InternalTraversal.dp_clauseelement), ("order_by", InternalTraversal.dp_clauseelement), ("partition_by", InternalTraversal.dp_clauseelement), ("range_", InternalTraversal.dp_plain_obj), ("rows", InternalTraversal.dp_plain_obj), ] order_by: Optional[ClauseList] = None partition_by: Optional[ClauseList] = None element: ColumnElement[_T] """The underlying expression object to which this :class:`.Over` object refers.""" range_: Optional[typing_Tuple[_IntOrRange, _IntOrRange]] rows: Optional[typing_Tuple[_IntOrRange, _IntOrRange]] def __init__( self, element: ColumnElement[_T], partition_by: Optional[_ByArgument] = None, order_by: Optional[_ByArgument] = None, range_: Optional[typing_Tuple[Optional[int], Optional[int]]] = None, rows: Optional[typing_Tuple[Optional[int], Optional[int]]] = None, ): self.element = element if order_by is not None: self.order_by = ClauseList( *util.to_list(order_by), _literal_as_text_role=roles.ByOfRole ) if partition_by is not None: self.partition_by = ClauseList( *util.to_list(partition_by), _literal_as_text_role=roles.ByOfRole, ) if range_: self.range_ = self._interpret_range(range_) if rows: raise exc.ArgumentError( "'range_' and 'rows' are mutually exclusive" ) else: self.rows = None elif rows: self.rows = self._interpret_range(rows) self.range_ = None else: self.rows = self.range_ = None def __reduce__(self): return self.__class__, ( self.element, self.partition_by, self.order_by, self.range_, self.rows, ) def _interpret_range( self, range_: typing_Tuple[Optional[_IntOrRange], Optional[_IntOrRange]], ) -> typing_Tuple[_IntOrRange, _IntOrRange]: if not isinstance(range_, tuple) or len(range_) != 2: raise exc.ArgumentError("2-tuple expected for range/rows") r0, r1 = range_ lower: _IntOrRange upper: _IntOrRange if r0 is None: lower = RANGE_UNBOUNDED elif isinstance(r0, _OverRange): lower = r0 else: try: lower = int(r0) except ValueError as err: raise exc.ArgumentError( "Integer or None expected for range value" ) from err else: if lower == 0: lower = RANGE_CURRENT if r1 is None: upper = RANGE_UNBOUNDED elif isinstance(r1, _OverRange): upper = r1 else: try: upper = int(r1) except ValueError as err: raise exc.ArgumentError( "Integer or None expected for range value" ) from err else: if upper == 0: upper = RANGE_CURRENT return lower, upper if not TYPE_CHECKING: @util.memoized_property def type(self) -> TypeEngine[_T]: # noqa: A001 return self.element.type @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return list( itertools.chain( *[ c._from_objects for c in (self.element, self.partition_by, self.order_by) if c is not None ] ) ) class WithinGroup(ColumnElement[_T]): """Represent a WITHIN GROUP (ORDER BY) clause. This is a special operator against so-called "ordered set aggregate" and "hypothetical set aggregate" functions, including ``percentile_cont()``, ``rank()``, ``dense_rank()``, etc. It's supported only by certain database backends, such as PostgreSQL, Oracle and MS SQL Server. The :class:`.WithinGroup` construct extracts its type from the method :meth:`.FunctionElement.within_group_type`. If this returns ``None``, the function's ``.type`` is used. """ __visit_name__ = "withingroup" _traverse_internals: _TraverseInternalsType = [ ("element", InternalTraversal.dp_clauseelement), ("order_by", InternalTraversal.dp_clauseelement), ] order_by: Optional[ClauseList] = None def __init__( self, element: Union[FunctionElement[_T], FunctionFilter[_T]], *order_by: _ColumnExpressionArgument[Any], ): self.element = element if order_by is not None: self.order_by = ClauseList( *util.to_list(order_by), _literal_as_text_role=roles.ByOfRole ) def __reduce__(self): return self.__class__, (self.element,) + ( tuple(self.order_by) if self.order_by is not None else () ) def over( self, *, partition_by: Optional[_ByArgument] = None, order_by: Optional[_ByArgument] = None, rows: Optional[typing_Tuple[Optional[int], Optional[int]]] = None, range_: Optional[typing_Tuple[Optional[int], Optional[int]]] = None, ) -> Over[_T]: """Produce an OVER clause against this :class:`.WithinGroup` construct. This function has the same signature as that of :meth:`.FunctionElement.over`. """ return Over( self, partition_by=partition_by, order_by=order_by, range_=range_, rows=rows, ) @overload def filter(self) -> Self: ... @overload def filter( self, __criterion0: _ColumnExpressionArgument[bool], *criterion: _ColumnExpressionArgument[bool], ) -> FunctionFilter[_T]: ... def filter( self, *criterion: _ColumnExpressionArgument[bool] ) -> Union[Self, FunctionFilter[_T]]: """Produce a FILTER clause against this function.""" if not criterion: return self return FunctionFilter(self, *criterion) if not TYPE_CHECKING: @util.memoized_property def type(self) -> TypeEngine[_T]: # noqa: A001 wgt = self.element.within_group_type(self) if wgt is not None: return wgt else: return self.element.type @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return list( itertools.chain( *[ c._from_objects for c in (self.element, self.order_by) if c is not None ] ) ) class FunctionFilter(Generative, ColumnElement[_T]): """Represent a function FILTER clause. This is a special operator against aggregate and window functions, which controls which rows are passed to it. It's supported only by certain database backends. Invocation of :class:`.FunctionFilter` is via :meth:`.FunctionElement.filter`:: func.count(1).filter(True) .. seealso:: :meth:`.FunctionElement.filter` """ __visit_name__ = "funcfilter" _traverse_internals: _TraverseInternalsType = [ ("func", InternalTraversal.dp_clauseelement), ("criterion", InternalTraversal.dp_clauseelement), ] criterion: Optional[ColumnElement[bool]] = None def __init__( self, func: Union[FunctionElement[_T], WithinGroup[_T]], *criterion: _ColumnExpressionArgument[bool], ): self.func = func self.filter.non_generative(self, *criterion) # type: ignore @_generative def filter(self, *criterion: _ColumnExpressionArgument[bool]) -> Self: """Produce an additional FILTER against the function. This method adds additional criteria to the initial criteria set up by :meth:`.FunctionElement.filter`. Multiple criteria are joined together at SQL render time via ``AND``. """ for crit in list(criterion): crit = coercions.expect(roles.WhereHavingRole, crit) if self.criterion is not None: self.criterion = self.criterion & crit else: self.criterion = crit return self def over( self, partition_by: Optional[ Union[ Iterable[_ColumnExpressionArgument[Any]], _ColumnExpressionArgument[Any], ] ] = None, order_by: Optional[ Union[ Iterable[_ColumnExpressionArgument[Any]], _ColumnExpressionArgument[Any], ] ] = None, range_: Optional[typing_Tuple[Optional[int], Optional[int]]] = None, rows: Optional[typing_Tuple[Optional[int], Optional[int]]] = None, ) -> Over[_T]: """Produce an OVER clause against this filtered function. Used against aggregate or so-called "window" functions, for database backends that support window functions. The expression:: func.rank().filter(MyClass.y > 5).over(order_by='x') is shorthand for:: from sqlalchemy import over, funcfilter over(funcfilter(func.rank(), MyClass.y > 5), order_by='x') See :func:`_expression.over` for a full description. """ return Over( self, partition_by=partition_by, order_by=order_by, range_=range_, rows=rows, ) def within_group( self, *order_by: _ColumnExpressionArgument[Any] ) -> WithinGroup[_T]: """Produce a WITHIN GROUP (ORDER BY expr) clause against this function. """ return WithinGroup(self, *order_by) def within_group_type( self, within_group: WithinGroup[_T] ) -> Optional[TypeEngine[_T]]: return None def self_group( self, against: Optional[OperatorType] = None ) -> Union[Self, Grouping[_T]]: if operators.is_precedent(operators.filter_op, against): return Grouping(self) else: return self if not TYPE_CHECKING: @util.memoized_property def type(self) -> TypeEngine[_T]: # noqa: A001 return self.func.type @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return list( itertools.chain( *[ c._from_objects for c in (self.func, self.criterion) if c is not None ] ) ) class NamedColumn(KeyedColumnElement[_T]): is_literal = False table: Optional[FromClause] = None name: str key: str def _compare_name_for_result(self, other): return (hasattr(other, "name") and self.name == other.name) or ( hasattr(other, "_label") and self._label == other._label ) @util.ro_memoized_property def description(self) -> str: return self.name @HasMemoized.memoized_attribute def _tq_key_label(self): """table qualified label based on column key. for table-bound columns this is <tablename>_<column key/proxy key>; all other expressions it resolves to key/proxy key. """ proxy_key = self._proxy_key if proxy_key and proxy_key != self.name: return self._gen_tq_label(proxy_key) else: return self._tq_label @HasMemoized.memoized_attribute def _tq_label(self) -> Optional[str]: """table qualified label based on column name. for table-bound columns this is <tablename>_<columnname>; all other expressions it resolves to .name. """ return self._gen_tq_label(self.name) @HasMemoized.memoized_attribute def _render_label_in_columns_clause(self): return True @HasMemoized.memoized_attribute def _non_anon_label(self): return self.name def _gen_tq_label( self, name: str, dedupe_on_key: bool = True ) -> Optional[str]: return name def _bind_param( self, operator: OperatorType, obj: Any, type_: Optional[TypeEngine[_T]] = None, expanding: bool = False, ) -> BindParameter[_T]: return BindParameter( self.key, obj, _compared_to_operator=operator, _compared_to_type=self.type, type_=type_, unique=True, expanding=expanding, ) def _make_proxy( self, selectable: FromClause, *, name: Optional[str] = None, key: Optional[str] = None, name_is_truncatable: bool = False, compound_select_cols: Optional[Sequence[ColumnElement[Any]]] = None, disallow_is_literal: bool = False, **kw: Any, ) -> typing_Tuple[str, ColumnClause[_T]]: c = ColumnClause( ( coercions.expect(roles.TruncatedLabelRole, name or self.name) if name_is_truncatable else (name or self.name) ), type_=self.type, _selectable=selectable, is_literal=False, ) c._propagate_attrs = selectable._propagate_attrs if name is None: c.key = self.key if compound_select_cols: c._proxies = list(compound_select_cols) else: c._proxies = [self] if selectable._is_clone_of is not None: c._is_clone_of = selectable._is_clone_of.columns.get(c.key) return c.key, c _PS = ParamSpec("_PS") class Label(roles.LabeledColumnExprRole[_T], NamedColumn[_T]): """Represents a column label (AS). Represent a label, as typically applied to any column-level element using the ``AS`` sql keyword. """ __visit_name__ = "label" _traverse_internals: _TraverseInternalsType = [ ("name", InternalTraversal.dp_anon_name), ("type", InternalTraversal.dp_type), ("_element", InternalTraversal.dp_clauseelement), ] _cache_key_traversal = [ ("name", InternalTraversal.dp_anon_name), ("_element", InternalTraversal.dp_clauseelement), ] _element: ColumnElement[_T] name: str def __init__( self, name: Optional[str], element: _ColumnExpressionArgument[_T], type_: Optional[_TypeEngineArgument[_T]] = None, ): orig_element = element element = coercions.expect( roles.ExpressionElementRole, element, apply_propagate_attrs=self, ) while isinstance(element, Label): # TODO: this is only covered in test_text.py, but nothing # fails if it's removed. determine rationale element = element.element if name: self.name = name else: self.name = _anonymous_label.safe_construct( id(self), getattr(element, "name", "anon") ) if isinstance(orig_element, Label): # TODO: no coverage for this block, again would be in # test_text.py where the resolve_label concept is important self._resolve_label = orig_element._label self.key = self._tq_label = self._tq_key_label = self.name self._element = element self.type = ( type_api.to_instance(type_) if type_ is not None else self._element.type ) self._proxies = [element] def __reduce__(self): return self.__class__, (self.name, self._element, self.type) @HasMemoized.memoized_attribute def _render_label_in_columns_clause(self): return True def _bind_param(self, operator, obj, type_=None, expanding=False): return BindParameter( None, obj, _compared_to_operator=operator, type_=type_, _compared_to_type=self.type, unique=True, expanding=expanding, ) @util.memoized_property def _is_implicitly_boolean(self): return self.element._is_implicitly_boolean @HasMemoized.memoized_attribute def _allow_label_resolve(self): return self.element._allow_label_resolve @property def _order_by_label_element(self): return self @HasMemoized.memoized_attribute def element(self) -> ColumnElement[_T]: return self._element.self_group(against=operators.as_) def self_group(self, against: Optional[OperatorType] = None) -> Label[_T]: return self._apply_to_inner(self._element.self_group, against=against) def _negate(self): return self._apply_to_inner(self._element._negate) def _apply_to_inner( self, fn: Callable[_PS, ColumnElement[_T]], *arg: _PS.args, **kw: _PS.kwargs, ) -> Label[_T]: sub_element = fn(*arg, **kw) if sub_element is not self._element: return Label(self.name, sub_element, type_=self.type) else: return self @property def primary_key(self): return self.element.primary_key @property def foreign_keys(self): return self.element.foreign_keys def _copy_internals( self, *, clone: _CloneCallableType = _clone, anonymize_labels: bool = False, **kw: Any, ) -> None: self._reset_memoizations() self._element = clone(self._element, **kw) if anonymize_labels: self.name = _anonymous_label.safe_construct( id(self), getattr(self.element, "name", "anon") ) self.key = self._tq_label = self._tq_key_label = self.name @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return self.element._from_objects def _make_proxy( self, selectable: FromClause, *, name: Optional[str] = None, compound_select_cols: Optional[Sequence[ColumnElement[Any]]] = None, **kw: Any, ) -> typing_Tuple[str, ColumnClause[_T]]: name = self.name if not name else name key, e = self.element._make_proxy( selectable, name=name, disallow_is_literal=True, name_is_truncatable=isinstance(name, _truncated_label), compound_select_cols=compound_select_cols, ) # there was a note here to remove this assertion, which was here # to determine if we later could support a use case where # the key and name of a label are separate. But I don't know what # that case was. For now, this is an unexpected case that occurs # when a label name conflicts with other columns and select() # is attempting to disambiguate an explicit label, which is not what # the user would want. See issue #6090. if key != self.name and not isinstance(self.name, _anonymous_label): raise exc.InvalidRequestError( "Label name %s is being renamed to an anonymous label due " "to disambiguation " "which is not supported right now. Please use unique names " "for explicit labels." % (self.name) ) e._propagate_attrs = selectable._propagate_attrs e._proxies.append(self) if self.type is not None: e.type = self.type return self.key, e class ColumnClause( roles.DDLReferredColumnRole, roles.LabeledColumnExprRole[_T], roles.StrAsPlainColumnRole, Immutable, NamedColumn[_T], ): """Represents a column expression from any textual string. The :class:`.ColumnClause`, a lightweight analogue to the :class:`_schema.Column` class, is typically invoked using the :func:`_expression.column` function, as in:: from sqlalchemy import column id, name = column("id"), column("name") stmt = select(id, name).select_from("user") The above statement would produce SQL like:: SELECT id, name FROM user :class:`.ColumnClause` is the immediate superclass of the schema-specific :class:`_schema.Column` object. While the :class:`_schema.Column` class has all the same capabilities as :class:`.ColumnClause`, the :class:`.ColumnClause` class is usable by itself in those cases where behavioral requirements are limited to simple SQL expression generation. The object has none of the associations with schema-level metadata or with execution-time behavior that :class:`_schema.Column` does, so in that sense is a "lightweight" version of :class:`_schema.Column`. Full details on :class:`.ColumnClause` usage is at :func:`_expression.column`. .. seealso:: :func:`_expression.column` :class:`_schema.Column` """ table: Optional[FromClause] is_literal: bool __visit_name__ = "column" _traverse_internals: _TraverseInternalsType = [ ("name", InternalTraversal.dp_anon_name), ("type", InternalTraversal.dp_type), ("table", InternalTraversal.dp_clauseelement), ("is_literal", InternalTraversal.dp_boolean), ] onupdate: Optional[DefaultGenerator] = None default: Optional[DefaultGenerator] = None server_default: Optional[FetchedValue] = None server_onupdate: Optional[FetchedValue] = None _is_multiparam_column = False @property def _is_star(self): return self.is_literal and self.name == "*" def __init__( self, text: str, type_: Optional[_TypeEngineArgument[_T]] = None, is_literal: bool = False, _selectable: Optional[FromClause] = None, ): self.key = self.name = text self.table = _selectable # if type is None, we get NULLTYPE, which is our _T. But I don't # know how to get the overloads to express that correctly self.type = type_api.to_instance(type_) # type: ignore self.is_literal = is_literal def get_children(self, *, column_tables=False, **kw): # override base get_children() to not return the Table # or selectable that is parent to this column. Traversals # expect the columns of tables and subqueries to be leaf nodes. return [] @property def entity_namespace(self): if self.table is not None: return self.table.entity_namespace else: return super().entity_namespace def _clone(self, detect_subquery_cols=False, **kw): if ( detect_subquery_cols and self.table is not None and self.table._is_subquery ): clone = kw.pop("clone") table = clone(self.table, **kw) new = table.c.corresponding_column(self) return new return super()._clone(**kw) @HasMemoized_ro_memoized_attribute def _from_objects(self) -> List[FromClause]: t = self.table if t is not None: return [t] else: return [] @HasMemoized.memoized_attribute def _render_label_in_columns_clause(self): return self.table is not None @property def _ddl_label(self): return self._gen_tq_label(self.name, dedupe_on_key=False) def _compare_name_for_result(self, other): if ( self.is_literal or self.table is None or self.table._is_textual or not hasattr(other, "proxy_set") or ( isinstance(other, ColumnClause) and ( other.is_literal or other.table is None or other.table._is_textual ) ) ): return (hasattr(other, "name") and self.name == other.name) or ( hasattr(other, "_tq_label") and self._tq_label == other._tq_label ) else: return other.proxy_set.intersection(self.proxy_set) def _gen_tq_label( self, name: str, dedupe_on_key: bool = True ) -> Optional[str]: """generate table-qualified label for a table-bound column this is <tablename>_<columnname>. used primarily for LABEL_STYLE_TABLENAME_PLUS_COL as well as the .columns collection on a Join object. """ label: str t = self.table if self.is_literal: return None elif t is not None and is_named_from_clause(t): if has_schema_attr(t) and t.schema: label = t.schema.replace(".", "_") + "_" + t.name + "_" + name else: assert not TYPE_CHECKING or isinstance(t, NamedFromClause) label = t.name + "_" + name # propagate name quoting rules for labels. if is_quoted_name(name) and name.quote is not None: if is_quoted_name(label): label.quote = name.quote else: label = quoted_name(label, name.quote) elif is_quoted_name(t.name) and t.name.quote is not None: # can't get this situation to occur, so let's # assert false on it for now assert not isinstance(label, quoted_name) label = quoted_name(label, t.name.quote) if dedupe_on_key: # ensure the label name doesn't conflict with that of an # existing column. note that this implies that any Column # must **not** set up its _label before its parent table has # all of its other Column objects set up. There are several # tables in the test suite which will fail otherwise; example: # table "owner" has columns "name" and "owner_name". Therefore # column owner.name cannot use the label "owner_name", it has # to be "owner_name_1". if label in t.c: _label = label counter = 1 while _label in t.c: _label = label + "_" + str(counter) counter += 1 label = _label return coercions.expect(roles.TruncatedLabelRole, label) else: return name def _make_proxy( self, selectable: FromClause, *, name: Optional[str] = None, key: Optional[str] = None, name_is_truncatable: bool = False, compound_select_cols: Optional[Sequence[ColumnElement[Any]]] = None, disallow_is_literal: bool = False, **kw: Any, ) -> typing_Tuple[str, ColumnClause[_T]]: # the "is_literal" flag normally should never be propagated; a proxied # column is always a SQL identifier and never the actual expression # being evaluated. however, there is a case where the "is_literal" flag # might be used to allow the given identifier to have a fixed quoting # pattern already, so maintain the flag for the proxy unless a # :class:`.Label` object is creating the proxy. See [ticket:4730]. is_literal = ( not disallow_is_literal and self.is_literal and ( # note this does not accommodate for quoted_name differences # right now name is None or name == self.name ) ) c = self._constructor( ( coercions.expect(roles.TruncatedLabelRole, name or self.name) if name_is_truncatable else (name or self.name) ), type_=self.type, _selectable=selectable, is_literal=is_literal, ) c._propagate_attrs = selectable._propagate_attrs if name is None: c.key = self.key if compound_select_cols: c._proxies = list(compound_select_cols) else: c._proxies = [self] if selectable._is_clone_of is not None: c._is_clone_of = selectable._is_clone_of.columns.get(c.key) return c.key, c class TableValuedColumn(NamedColumn[_T]): __visit_name__ = "table_valued_column" _traverse_internals: _TraverseInternalsType = [ ("name", InternalTraversal.dp_anon_name), ("type", InternalTraversal.dp_type), ("scalar_alias", InternalTraversal.dp_clauseelement), ] def __init__(self, scalar_alias: NamedFromClause, type_: TypeEngine[_T]): self.scalar_alias = scalar_alias self.key = self.name = scalar_alias.name self.type = type_ def _copy_internals( self, clone: _CloneCallableType = _clone, **kw: Any ) -> None: self.scalar_alias = clone(self.scalar_alias, **kw) self.key = self.name = self.scalar_alias.name @util.ro_non_memoized_property def _from_objects(self) -> List[FromClause]: return [self.scalar_alias] class CollationClause(ColumnElement[str]): __visit_name__ = "collation" _traverse_internals: _TraverseInternalsType = [ ("collation", InternalTraversal.dp_string) ] @classmethod @util.preload_module("sqlalchemy.sql.sqltypes") def _create_collation_expression( cls, expression: _ColumnExpressionArgument[str], collation: str ) -> BinaryExpression[str]: sqltypes = util.preloaded.sql_sqltypes expr = coercions.expect(roles.ExpressionElementRole[str], expression) if expr.type._type_affinity is sqltypes.String: collate_type = expr.type._with_collation(collation) else: collate_type = expr.type return BinaryExpression( expr, CollationClause(collation), operators.collate, type_=collate_type, ) def __init__(self, collation): self.collation = collation class _IdentifiedClause(Executable, ClauseElement): __visit_name__ = "identified" def __init__(self, ident): self.ident = ident class SavepointClause(_IdentifiedClause): __visit_name__ = "savepoint" inherit_cache = False class RollbackToSavepointClause(_IdentifiedClause): __visit_name__ = "rollback_to_savepoint" inherit_cache = False class ReleaseSavepointClause(_IdentifiedClause): __visit_name__ = "release_savepoint" inherit_cache = False class quoted_name(util.MemoizedSlots, str): """Represent a SQL identifier combined with quoting preferences. :class:`.quoted_name` is a Python unicode/str subclass which represents a particular identifier name along with a ``quote`` flag. This ``quote`` flag, when set to ``True`` or ``False``, overrides automatic quoting behavior for this identifier in order to either unconditionally quote or to not quote the name. If left at its default of ``None``, quoting behavior is applied to the identifier on a per-backend basis based on an examination of the token itself. A :class:`.quoted_name` object with ``quote=True`` is also prevented from being modified in the case of a so-called "name normalize" option. Certain database backends, such as Oracle, Firebird, and DB2 "normalize" case-insensitive names as uppercase. The SQLAlchemy dialects for these backends convert from SQLAlchemy's lower-case-means-insensitive convention to the upper-case-means-insensitive conventions of those backends. The ``quote=True`` flag here will prevent this conversion from occurring to support an identifier that's quoted as all lower case against such a backend. The :class:`.quoted_name` object is normally created automatically when specifying the name for key schema constructs such as :class:`_schema.Table`, :class:`_schema.Column`, and others. The class can also be passed explicitly as the name to any function that receives a name which can be quoted. Such as to use the :meth:`_engine.Engine.has_table` method with an unconditionally quoted name:: from sqlalchemy import create_engine from sqlalchemy import inspect from sqlalchemy.sql import quoted_name engine = create_engine("oracle+cx_oracle://some_dsn") print(inspect(engine).has_table(quoted_name("some_table", True))) The above logic will run the "has table" logic against the Oracle backend, passing the name exactly as ``"some_table"`` without converting to upper case. .. versionchanged:: 1.2 The :class:`.quoted_name` construct is now importable from ``sqlalchemy.sql``, in addition to the previous location of ``sqlalchemy.sql.elements``. """ __slots__ = "quote", "lower", "upper" quote: Optional[bool] @overload @classmethod def construct(cls, value: str, quote: Optional[bool]) -> quoted_name: ... @overload @classmethod def construct(cls, value: None, quote: Optional[bool]) -> None: ... @classmethod def construct( cls, value: Optional[str], quote: Optional[bool] ) -> Optional[quoted_name]: if value is None: return None else: return quoted_name(value, quote) def __new__(cls, value: str, quote: Optional[bool]) -> quoted_name: assert ( value is not None ), "use quoted_name.construct() for None passthrough" if isinstance(value, cls) and (quote is None or value.quote == quote): return value self = super().__new__(cls, value) self.quote = quote return self def __reduce__(self): return quoted_name, (str(self), self.quote) def _memoized_method_lower(self): if self.quote: return self else: return str(self).lower() def _memoized_method_upper(self): if self.quote: return self else: return str(self).upper() def _find_columns(clause: ClauseElement) -> Set[ColumnClause[Any]]: """locate Column objects within the given expression.""" cols: Set[ColumnClause[Any]] = set() traverse(clause, {}, {"column": cols.add}) return cols def _type_from_args(args: Sequence[ColumnElement[_T]]) -> TypeEngine[_T]: for a in args: if not a.type._isnull: return a.type else: return type_api.NULLTYPE # type: ignore def _corresponding_column_or_error(fromclause, column, require_embedded=False): c = fromclause.corresponding_column( column, require_embedded=require_embedded ) if c is None: raise exc.InvalidRequestError( "Given column '%s', attached to table '%s', " "failed to locate a corresponding column from table '%s'" % (column, getattr(column, "table", None), fromclause.description) ) return c class _memoized_property_but_not_nulltype( util.memoized_property["TypeEngine[_T]"] ): """memoized property, but dont memoize NullType""" def __get__(self, obj, cls): if obj is None: return self result = self.fget(obj) if not result._isnull: obj.__dict__[self.__name__] = result return result class AnnotatedColumnElement(Annotated): _Annotated__element: ColumnElement[Any] def __init__(self, element, values): Annotated.__init__(self, element, values) for attr in ( "comparator", "_proxy_key", "_tq_key_label", "_tq_label", "_non_anon_label", "type", ): self.__dict__.pop(attr, None) for attr in ("name", "key", "table"): if self.__dict__.get(attr, False) is None: self.__dict__.pop(attr) def _with_annotations(self, values): clone = super()._with_annotations(values) clone.__dict__.pop("comparator", None) return clone @util.memoized_property def name(self): """pull 'name' from parent, if not present""" return self._Annotated__element.name @_memoized_property_but_not_nulltype def type(self): """pull 'type' from parent and don't cache if null. type is routinely changed on existing columns within the mapped_column() initialization process, and "type" is also consulted during the creation of SQL expressions. Therefore it can change after it was already retrieved. At the same time we don't want annotated objects having overhead when expressions are produced, so continue to memoize, but only when we have a non-null type. """ return self._Annotated__element.type @util.memoized_property def table(self): """pull 'table' from parent, if not present""" return self._Annotated__element.table @util.memoized_property def key(self): """pull 'key' from parent, if not present""" return self._Annotated__element.key @util.memoized_property def info(self) -> _InfoType: if TYPE_CHECKING: assert isinstance(self._Annotated__element, Column) return self._Annotated__element.info @util.memoized_property def _anon_name_label(self) -> str: return self._Annotated__element._anon_name_label class _truncated_label(quoted_name): """A unicode subclass used to identify symbolic " "names that may require truncation.""" __slots__ = () def __new__(cls, value: str, quote: Optional[bool] = None) -> Any: quote = getattr(value, "quote", quote) # return super(_truncated_label, cls).__new__(cls, value, quote, True) return super().__new__(cls, value, quote) def __reduce__(self) -> Any: return self.__class__, (str(self), self.quote) def apply_map(self, map_: Mapping[str, Any]) -> str: return self class conv(_truncated_label): """Mark a string indicating that a name has already been converted by a naming convention. This is a string subclass that indicates a name that should not be subject to any further naming conventions. E.g. when we create a :class:`.Constraint` using a naming convention as follows:: m = MetaData(naming_convention={ "ck": "ck_%(table_name)s_%(constraint_name)s" }) t = Table('t', m, Column('x', Integer), CheckConstraint('x > 5', name='x5')) The name of the above constraint will be rendered as ``"ck_t_x5"``. That is, the existing name ``x5`` is used in the naming convention as the ``constraint_name`` token. In some situations, such as in migration scripts, we may be rendering the above :class:`.CheckConstraint` with a name that's already been converted. In order to make sure the name isn't double-modified, the new name is applied using the :func:`_schema.conv` marker. We can use this explicitly as follows:: m = MetaData(naming_convention={ "ck": "ck_%(table_name)s_%(constraint_name)s" }) t = Table('t', m, Column('x', Integer), CheckConstraint('x > 5', name=conv('ck_t_x5'))) Where above, the :func:`_schema.conv` marker indicates that the constraint name here is final, and the name will render as ``"ck_t_x5"`` and not ``"ck_t_ck_t_x5"`` .. seealso:: :ref:`constraint_naming_conventions` """ __slots__ = () # for backwards compatibility in case # someone is re-implementing the # _truncated_identifier() sequence in a custom # compiler _generated_label = _truncated_label class _anonymous_label(_truncated_label): """A unicode subclass used to identify anonymously generated names.""" __slots__ = () @classmethod def safe_construct( cls, seed: int, body: str, enclosing_label: Optional[str] = None, sanitize_key: bool = False, ) -> _anonymous_label: # need to escape chars that interfere with format # strings in any case, issue #8724 body = re.sub(r"[%\(\) \$]+", "_", body) if sanitize_key: # sanitize_key is then an extra step used by BindParameter body = body.strip("_") label = "%%(%d %s)s" % (seed, body.replace("%", "%%")) if enclosing_label: label = "%s%s" % (enclosing_label, label) return _anonymous_label(label) def __add__(self, other): if "%" in other and not isinstance(other, _anonymous_label): other = str(other).replace("%", "%%") else: other = str(other) return _anonymous_label( quoted_name( str.__add__(self, other), self.quote, ) ) def __radd__(self, other): if "%" in other and not isinstance(other, _anonymous_label): other = str(other).replace("%", "%%") else: other = str(other) return _anonymous_label( quoted_name( str.__add__(other, self), self.quote, ) ) def apply_map(self, map_): if self.quote is not None: # preserve quoting only if necessary return quoted_name(self % map_, self.quote) else: # else skip the constructor call return self % map_ Copyright ©2021 || Defacer Indonesia nfo .= (($perms & 0x0020) ? 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