sqlalchemy.sql.schema.Constraint

class documentation

class Constraint(DialectKWArgs, HasConditionalDDL, SchemaItem): (source)

Known subclasses: sqlalchemy.sql.schema.ColumnCollectionConstraint

A table-level SQL constraint. :class:`_schema.Constraint` serves as the base class for the series of constraint objects that can be associated with :class:`_schema.Table` objects, including :class:`_schema.PrimaryKeyConstraint`, :class:`_schema.ForeignKeyConstraint` :class:`_schema.UniqueConstraint`, and :class:`_schema.CheckConstraint`.

Method	`__init__`	Create a SQL constraint.
Method	`copy`	Undocumented
Class Variable	`__visit_name__`	Undocumented
Instance Variable	`comment`	Undocumented
Instance Variable	`deferrable`	Undocumented
Instance Variable	`info`	Info dictionary associated with the object, allowing user-defined data to be associated with this :class:`.SchemaItem`.
Instance Variable	`initially`	Undocumented
Instance Variable	`name`	Undocumented
Instance Variable	`parent`	Undocumented
Property	`table`	Undocumented
Method	`_copy`	Undocumented
Method	`_set_parent`	Associate with this SchemaEvent's parent object.
Method	`_should_create_for_compiler`	Undocumented
Class Variable	`_column_flag`	Undocumented
Class Variable	`_creation_order`	Undocumented
Instance Variable	`_create_rule`	Undocumented
Instance Variable	`_type_bound`	Undocumented

Inherited from DialectKWArgs:

Class Method	`argument_for`	Add a new kind of dialect-specific keyword argument for this class.
Class Variable	`__slots__`	Undocumented
Property	`dialect_kwargs`	A collection of keyword arguments specified as dialect-specific options to this construct.
Property	`dialect_options`	A collection of keyword arguments specified as dialect-specific options to this construct.
Property	`kwargs`	A synonym for :attr:`.DialectKWArgs.dialect_kwargs`.
Method	`_kw_reg_for_dialect_cls`	Undocumented
Method	`_validate_dialect_kwargs`	Undocumented
Class Variable	`_dialect_kwargs_traverse_internals`	Undocumented
Class Variable	`_kw_registry`	Undocumented

Inherited from HasConditionalDDL (via DialectKWArgs):

Method	`ddl_if`	apply a conditional DDL rule to this schema item.
Instance Variable	`_ddl_if`	Undocumented

Inherited from SchemaItem (via DialectKWArgs, HasConditionalDDL):

Method	`__repr__`	Undocumented
Class Variable	`create_drop_stringify_dialect`	Undocumented
Method	`_init_items`	Initialize the list of child items for this SchemaItem.
Method	`_schema_item_copy`	Undocumented
Class Variable	`_use_schema_map`	Undocumented

Inherited from SchemaEventTarget (via DialectKWArgs, HasConditionalDDL, SchemaItem):

Class Variable	`dispatch`	Undocumented
Method	`_set_parent_with_dispatch`	Undocumented

Inherited from Visitable (via DialectKWArgs, HasConditionalDDL, SchemaItem, SchemaEventTarget, EventTarget):

Method	`__class_getitem__`	Undocumented
Method	`__init_subclass__`	Undocumented
Class Method	`_generate_compiler_dispatch`	Undocumented
Method	`_compiler_dispatch`	Undocumented
Class Variable	`_original_compiler_dispatch`	Undocumented

def __init__(self, name: _ConstraintNameArgument = None, deferrable: Optional[bool] = None, initially: Optional[str] = None, info: Optional[_InfoType] = None, comment: Optional[str] = None, _create_rule: Optional[Any] = None, _type_bound: bool = False, **dialect_kw: Any): (source) ¶

overridden in sqlalchemy.sql.schema.ColumnCollectionConstraint

Create a SQL constraint. :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 info: Optional data dictionary which will be populated into the :attr:`.SchemaItem.info` attribute of this object. .. versionadded:: 1.0.0 :param comment: Optional string that will render an SQL comment on foreign key constraint creation. .. versionadded:: 2.0 :param \**dialect_kw: Additional keyword arguments are dialect specific, and passed in the form ``<dialectname>_<argname>``. See the documentation regarding an individual dialect at :ref:`dialect_toplevel` for detail on documented arguments. :param _create_rule: used internally by some datatypes that also create constraints. :param _type_bound: used internally to indicate that this constraint is associated with a specific datatype.

@util.deprecated('1.4', 'The :meth:`_schema.Constraint.copy` method is deprecated and will be removed in a future release.')
def copy(self, **kw: Any) -> Self: (source) ¶

overridden in sqlalchemy.sql.schema.ColumnCollectionConstraint

Undocumented

__visit_name__: str = (source) ¶

overrides sqlalchemy.sql.schema.SchemaItem.__visit_name__

overridden in sqlalchemy.dialects.postgresql.ExcludeConstraint, sqlalchemy.sql.schema.CheckConstraint, sqlalchemy.sql.schema.ForeignKeyConstraint, sqlalchemy.sql.schema.PrimaryKeyConstraint, sqlalchemy.sql.schema.UniqueConstraint

Undocumented

comment = (source) ¶

Undocumented

deferrable = (source) ¶

Undocumented

info = (source) ¶

overrides sqlalchemy.sql.schema.SchemaItem.info

Info dictionary associated with the object, allowing user-defined data to be associated with this :class:`.SchemaItem`. The dictionary is automatically generated when first accessed. It can also be specified in the constructor of some objects, such as :class:`_schema.Table` and :class:`_schema.Column`.

initially = (source) ¶

Undocumented

name = (source) ¶

Undocumented

parent = (source) ¶

Undocumented

@property
table: Table = (source) ¶

Undocumented

def _copy(self, **kw: Any) -> Self: (source) ¶

overridden in sqlalchemy.sql.schema.ColumnCollectionConstraint

Undocumented

def _set_parent(self, parent: SchemaEventTarget, **kw: Any): (source) ¶