sqlalchemy.sql.schema.HasConditionalDDL

class documentation

class HasConditionalDDL: (source)

Known subclasses: sqlalchemy.sql.schema.Constraint, sqlalchemy.sql.schema.Index

define a class that includes the :meth:`.HasConditionalDDL.ddl_if` method, allowing for conditional rendering of DDL. Currently applies to constraints and indexes. .. versionadded:: 2.0

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

def ddl_if(self, dialect: Optional[str] = None, callable_: Optional[ddl.DDLIfCallable] = None, state: Optional[Any] = None) -> Self: (source) ¶

apply a conditional DDL rule to this schema item. These rules work in a similar manner to the :meth:`.ExecutableDDLElement.execute_if` callable, with the added feature that the criteria may be checked within the DDL compilation phase for a construct such as :class:`.CreateTable`. :meth:`.HasConditionalDDL.ddl_if` currently applies towards the :class:`.Index` construct as well as all :class:`.Constraint` constructs. :param dialect: string name of a dialect, or a tuple of string names to indicate multiple dialect types. :param callable\_: a callable that is constructed using the same form as that described in :paramref:`.ExecutableDDLElement.execute_if.callable_`. :param state: any arbitrary object that will be passed to the callable, if present. .. versionadded:: 2.0 .. seealso:: :ref:`schema_ddl_ddl_if` - background and usage examples

_ddl_if = (source) ¶

Undocumented