# 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 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
_T = TypeVar("_T", bound=Any)
if TYPE_CHECKING:
from ...sql.visitors import _TraverseInternalsType
class aggregate_order_by(expression.ColumnElement):
"""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),
]
def __init__(self, target, *order_by):
self.target = coercions.expect(roles.ExpressionElementRole, target)
self.type = self.target.type
_lob = len(order_by)
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=None):
return self
def get_children(self, **kwargs):
return self.target, self.order_by
def _copy_internals(self, clone=elements._clone, **kw):
self.target = clone(self.target, **kw)
self.order_by = clone(self.order_by, **kw)
@property
def _from_objects(self):
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)
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