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- # dialects/postgresql/ext.py
- # Copyright (C) 2005-2025 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: ignore-errors
- from __future__ import annotations
- from typing import Any
- from typing import Iterable
- from typing import List
- from typing import Optional
- from typing import overload
- from typing import TYPE_CHECKING
- from typing import TypeVar
- from . import types
- from .array import ARRAY
- from ...sql import coercions
- from ...sql import elements
- from ...sql import expression
- from ...sql import functions
- from ...sql import roles
- from ...sql import schema
- from ...sql.schema import ColumnCollectionConstraint
- from ...sql.sqltypes import TEXT
- from ...sql.visitors import InternalTraversal
- if TYPE_CHECKING:
- from ...sql._typing import _ColumnExpressionArgument
- from ...sql.elements import ClauseElement
- from ...sql.elements import ColumnElement
- from ...sql.operators import OperatorType
- from ...sql.selectable import FromClause
- from ...sql.visitors import _CloneCallableType
- from ...sql.visitors import _TraverseInternalsType
- _T = TypeVar("_T", bound=Any)
- class aggregate_order_by(expression.ColumnElement[_T]):
- """Represent a PostgreSQL aggregate order by expression.
- E.g.::
- from sqlalchemy.dialects.postgresql import aggregate_order_by
- expr = func.array_agg(aggregate_order_by(table.c.a, table.c.b.desc()))
- stmt = select(expr)
- would represent the expression:
- .. sourcecode:: sql
- SELECT array_agg(a ORDER BY b DESC) FROM table;
- Similarly::
- expr = func.string_agg(
- table.c.a, aggregate_order_by(literal_column("','"), table.c.a)
- )
- stmt = select(expr)
- Would represent:
- .. sourcecode:: sql
- SELECT string_agg(a, ',' ORDER BY a) FROM table;
- .. versionchanged:: 1.2.13 - the ORDER BY argument may be multiple terms
- .. seealso::
- :class:`_functions.array_agg`
- """
- __visit_name__ = "aggregate_order_by"
- stringify_dialect = "postgresql"
- _traverse_internals: _TraverseInternalsType = [
- ("target", InternalTraversal.dp_clauseelement),
- ("type", InternalTraversal.dp_type),
- ("order_by", InternalTraversal.dp_clauseelement),
- ]
- @overload
- def __init__(
- self,
- target: ColumnElement[_T],
- *order_by: _ColumnExpressionArgument[Any],
- ): ...
- @overload
- def __init__(
- self,
- target: _ColumnExpressionArgument[_T],
- *order_by: _ColumnExpressionArgument[Any],
- ): ...
- def __init__(
- self,
- target: _ColumnExpressionArgument[_T],
- *order_by: _ColumnExpressionArgument[Any],
- ):
- self.target: ClauseElement = coercions.expect(
- roles.ExpressionElementRole, target
- )
- self.type = self.target.type
- _lob = len(order_by)
- self.order_by: ClauseElement
- if _lob == 0:
- raise TypeError("at least one ORDER BY element is required")
- elif _lob == 1:
- self.order_by = coercions.expect(
- roles.ExpressionElementRole, order_by[0]
- )
- else:
- self.order_by = elements.ClauseList(
- *order_by, _literal_as_text_role=roles.ExpressionElementRole
- )
- def self_group(
- self, against: Optional[OperatorType] = None
- ) -> ClauseElement:
- return self
- def get_children(self, **kwargs: Any) -> Iterable[ClauseElement]:
- return self.target, self.order_by
- def _copy_internals(
- self, clone: _CloneCallableType = elements._clone, **kw: Any
- ) -> None:
- self.target = clone(self.target, **kw)
- self.order_by = clone(self.order_by, **kw)
- @property
- def _from_objects(self) -> List[FromClause]:
- return self.target._from_objects + self.order_by._from_objects
- class ExcludeConstraint(ColumnCollectionConstraint):
- """A table-level EXCLUDE constraint.
- Defines an EXCLUDE constraint as described in the `PostgreSQL
- documentation`__.
- __ https://www.postgresql.org/docs/current/static/sql-createtable.html#SQL-CREATETABLE-EXCLUDE
- """ # noqa
- __visit_name__ = "exclude_constraint"
- where = None
- inherit_cache = False
- create_drop_stringify_dialect = "postgresql"
- @elements._document_text_coercion(
- "where",
- ":class:`.ExcludeConstraint`",
- ":paramref:`.ExcludeConstraint.where`",
- )
- def __init__(self, *elements, **kw):
- r"""
- Create an :class:`.ExcludeConstraint` object.
- E.g.::
- const = ExcludeConstraint(
- (Column("period"), "&&"),
- (Column("group"), "="),
- where=(Column("group") != "some group"),
- ops={"group": "my_operator_class"},
- )
- The constraint is normally embedded into the :class:`_schema.Table`
- construct
- directly, or added later using :meth:`.append_constraint`::
- some_table = Table(
- "some_table",
- metadata,
- Column("id", Integer, primary_key=True),
- Column("period", TSRANGE()),
- Column("group", String),
- )
- some_table.append_constraint(
- ExcludeConstraint(
- (some_table.c.period, "&&"),
- (some_table.c.group, "="),
- where=some_table.c.group != "some group",
- name="some_table_excl_const",
- ops={"group": "my_operator_class"},
- )
- )
- The exclude constraint defined in this example requires the
- ``btree_gist`` extension, that can be created using the
- command ``CREATE EXTENSION btree_gist;``.
- :param \*elements:
- A sequence of two tuples of the form ``(column, operator)`` where
- "column" is either a :class:`_schema.Column` object, or a SQL
- expression element (e.g. ``func.int8range(table.from, table.to)``)
- or the name of a column as string, and "operator" is a string
- containing the operator to use (e.g. `"&&"` or `"="`).
- In order to specify a column name when a :class:`_schema.Column`
- object is not available, while ensuring
- that any necessary quoting rules take effect, an ad-hoc
- :class:`_schema.Column` or :func:`_expression.column`
- object should be used.
- The ``column`` may also be a string SQL expression when
- passed as :func:`_expression.literal_column` or
- :func:`_expression.text`
- :param name:
- Optional, the in-database name of this constraint.
- :param deferrable:
- Optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when
- issuing DDL for this constraint.
- :param initially:
- Optional string. If set, emit INITIALLY <value> when issuing DDL
- for this constraint.
- :param using:
- Optional string. If set, emit USING <index_method> when issuing DDL
- for this constraint. Defaults to 'gist'.
- :param where:
- Optional SQL expression construct or literal SQL string.
- If set, emit WHERE <predicate> when issuing DDL
- for this constraint.
- :param ops:
- Optional dictionary. Used to define operator classes for the
- elements; works the same way as that of the
- :ref:`postgresql_ops <postgresql_operator_classes>`
- parameter specified to the :class:`_schema.Index` construct.
- .. versionadded:: 1.3.21
- .. seealso::
- :ref:`postgresql_operator_classes` - general description of how
- PostgreSQL operator classes are specified.
- """
- columns = []
- render_exprs = []
- self.operators = {}
- expressions, operators = zip(*elements)
- for (expr, column, strname, add_element), operator in zip(
- coercions.expect_col_expression_collection(
- roles.DDLConstraintColumnRole, expressions
- ),
- operators,
- ):
- if add_element is not None:
- columns.append(add_element)
- name = column.name if column is not None else strname
- if name is not None:
- # backwards compat
- self.operators[name] = operator
- render_exprs.append((expr, name, operator))
- self._render_exprs = render_exprs
- ColumnCollectionConstraint.__init__(
- self,
- *columns,
- name=kw.get("name"),
- deferrable=kw.get("deferrable"),
- initially=kw.get("initially"),
- )
- self.using = kw.get("using", "gist")
- where = kw.get("where")
- if where is not None:
- self.where = coercions.expect(roles.StatementOptionRole, where)
- self.ops = kw.get("ops", {})
- def _set_parent(self, table, **kw):
- super()._set_parent(table)
- self._render_exprs = [
- (
- expr if not isinstance(expr, str) else table.c[expr],
- name,
- operator,
- )
- for expr, name, operator in (self._render_exprs)
- ]
- def _copy(self, target_table=None, **kw):
- elements = [
- (
- schema._copy_expression(expr, self.parent, target_table),
- operator,
- )
- for expr, _, operator in self._render_exprs
- ]
- c = self.__class__(
- *elements,
- name=self.name,
- deferrable=self.deferrable,
- initially=self.initially,
- where=self.where,
- using=self.using,
- )
- c.dispatch._update(self.dispatch)
- return c
- def array_agg(*arg, **kw):
- """PostgreSQL-specific form of :class:`_functions.array_agg`, ensures
- return type is :class:`_postgresql.ARRAY` and not
- the plain :class:`_types.ARRAY`, unless an explicit ``type_``
- is passed.
- """
- kw["_default_array_type"] = ARRAY
- return functions.func.array_agg(*arg, **kw)
- class _regconfig_fn(functions.GenericFunction[_T]):
- inherit_cache = True
- def __init__(self, *args, **kwargs):
- args = list(args)
- if len(args) > 1:
- initial_arg = coercions.expect(
- roles.ExpressionElementRole,
- args.pop(0),
- name=getattr(self, "name", None),
- apply_propagate_attrs=self,
- type_=types.REGCONFIG,
- )
- initial_arg = [initial_arg]
- else:
- initial_arg = []
- addtl_args = [
- coercions.expect(
- roles.ExpressionElementRole,
- c,
- name=getattr(self, "name", None),
- apply_propagate_attrs=self,
- )
- for c in args
- ]
- super().__init__(*(initial_arg + addtl_args), **kwargs)
- class to_tsvector(_regconfig_fn):
- """The PostgreSQL ``to_tsvector`` SQL function.
- This function applies automatic casting of the REGCONFIG argument
- to use the :class:`_postgresql.REGCONFIG` datatype automatically,
- and applies a return type of :class:`_postgresql.TSVECTOR`.
- Assuming the PostgreSQL dialect has been imported, either by invoking
- ``from sqlalchemy.dialects import postgresql``, or by creating a PostgreSQL
- engine using ``create_engine("postgresql...")``,
- :class:`_postgresql.to_tsvector` will be used automatically when invoking
- ``sqlalchemy.func.to_tsvector()``, ensuring the correct argument and return
- type handlers are used at compile and execution time.
- .. versionadded:: 2.0.0rc1
- """
- inherit_cache = True
- type = types.TSVECTOR
- class to_tsquery(_regconfig_fn):
- """The PostgreSQL ``to_tsquery`` SQL function.
- This function applies automatic casting of the REGCONFIG argument
- to use the :class:`_postgresql.REGCONFIG` datatype automatically,
- and applies a return type of :class:`_postgresql.TSQUERY`.
- Assuming the PostgreSQL dialect has been imported, either by invoking
- ``from sqlalchemy.dialects import postgresql``, or by creating a PostgreSQL
- engine using ``create_engine("postgresql...")``,
- :class:`_postgresql.to_tsquery` will be used automatically when invoking
- ``sqlalchemy.func.to_tsquery()``, ensuring the correct argument and return
- type handlers are used at compile and execution time.
- .. versionadded:: 2.0.0rc1
- """
- inherit_cache = True
- type = types.TSQUERY
- class plainto_tsquery(_regconfig_fn):
- """The PostgreSQL ``plainto_tsquery`` SQL function.
- This function applies automatic casting of the REGCONFIG argument
- to use the :class:`_postgresql.REGCONFIG` datatype automatically,
- and applies a return type of :class:`_postgresql.TSQUERY`.
- Assuming the PostgreSQL dialect has been imported, either by invoking
- ``from sqlalchemy.dialects import postgresql``, or by creating a PostgreSQL
- engine using ``create_engine("postgresql...")``,
- :class:`_postgresql.plainto_tsquery` will be used automatically when
- invoking ``sqlalchemy.func.plainto_tsquery()``, ensuring the correct
- argument and return type handlers are used at compile and execution time.
- .. versionadded:: 2.0.0rc1
- """
- inherit_cache = True
- type = types.TSQUERY
- class phraseto_tsquery(_regconfig_fn):
- """The PostgreSQL ``phraseto_tsquery`` SQL function.
- This function applies automatic casting of the REGCONFIG argument
- to use the :class:`_postgresql.REGCONFIG` datatype automatically,
- and applies a return type of :class:`_postgresql.TSQUERY`.
- Assuming the PostgreSQL dialect has been imported, either by invoking
- ``from sqlalchemy.dialects import postgresql``, or by creating a PostgreSQL
- engine using ``create_engine("postgresql...")``,
- :class:`_postgresql.phraseto_tsquery` will be used automatically when
- invoking ``sqlalchemy.func.phraseto_tsquery()``, ensuring the correct
- argument and return type handlers are used at compile and execution time.
- .. versionadded:: 2.0.0rc1
- """
- inherit_cache = True
- type = types.TSQUERY
- class websearch_to_tsquery(_regconfig_fn):
- """The PostgreSQL ``websearch_to_tsquery`` SQL function.
- This function applies automatic casting of the REGCONFIG argument
- to use the :class:`_postgresql.REGCONFIG` datatype automatically,
- and applies a return type of :class:`_postgresql.TSQUERY`.
- Assuming the PostgreSQL dialect has been imported, either by invoking
- ``from sqlalchemy.dialects import postgresql``, or by creating a PostgreSQL
- engine using ``create_engine("postgresql...")``,
- :class:`_postgresql.websearch_to_tsquery` will be used automatically when
- invoking ``sqlalchemy.func.websearch_to_tsquery()``, ensuring the correct
- argument and return type handlers are used at compile and execution time.
- .. versionadded:: 2.0.0rc1
- """
- inherit_cache = True
- type = types.TSQUERY
- class ts_headline(_regconfig_fn):
- """The PostgreSQL ``ts_headline`` SQL function.
- This function applies automatic casting of the REGCONFIG argument
- to use the :class:`_postgresql.REGCONFIG` datatype automatically,
- and applies a return type of :class:`_types.TEXT`.
- Assuming the PostgreSQL dialect has been imported, either by invoking
- ``from sqlalchemy.dialects import postgresql``, or by creating a PostgreSQL
- engine using ``create_engine("postgresql...")``,
- :class:`_postgresql.ts_headline` will be used automatically when invoking
- ``sqlalchemy.func.ts_headline()``, ensuring the correct argument and return
- type handlers are used at compile and execution time.
- .. versionadded:: 2.0.0rc1
- """
- inherit_cache = True
- type = TEXT
- def __init__(self, *args, **kwargs):
- args = list(args)
- # parse types according to
- # https://www.postgresql.org/docs/current/textsearch-controls.html#TEXTSEARCH-HEADLINE
- if len(args) < 2:
- # invalid args; don't do anything
- has_regconfig = False
- elif (
- isinstance(args[1], elements.ColumnElement)
- and args[1].type._type_affinity is types.TSQUERY
- ):
- # tsquery is second argument, no regconfig argument
- has_regconfig = False
- else:
- has_regconfig = True
- if has_regconfig:
- initial_arg = coercions.expect(
- roles.ExpressionElementRole,
- args.pop(0),
- apply_propagate_attrs=self,
- name=getattr(self, "name", None),
- type_=types.REGCONFIG,
- )
- initial_arg = [initial_arg]
- else:
- initial_arg = []
- addtl_args = [
- coercions.expect(
- roles.ExpressionElementRole,
- c,
- name=getattr(self, "name", None),
- apply_propagate_attrs=self,
- )
- for c in args
- ]
- super().__init__(*(initial_arg + addtl_args), **kwargs)
|