Vous êtes un professionnel et vous avez besoin d'une formation ? Programmation Python
Les compléments Voir le programme détaillé

Module « sqlalchemy.orm »

Fonction polymorphic_union - module sqlalchemy.orm

Signature de la fonction polymorphic_union

def polymorphic_union(table_map, typecolname, aliasname='p_union', cast_nulls=True) 

Description

help(sqlalchemy.orm.polymorphic_union)

Create a ``UNION`` statement used by a polymorphic mapper.

See  :ref:`concrete_inheritance` for an example of how
this is used.

:param table_map: mapping of polymorphic identities to
 :class:`_schema.Table` objects.
:param typecolname: string name of a "discriminator" column, which will be
 derived from the query, producing the polymorphic identity for
 each row.  If ``None``, no polymorphic discriminator is generated.
:param aliasname: name of the :func:`~sqlalchemy.sql.expression.alias()`
 construct generated.
:param cast_nulls: if True, non-existent columns, which are represented
 as labeled NULLs, will be passed into CAST.   This is a legacy behavior
 that is problematic on some backends such as Oracle - in which case it
 can be set to False.

Vous êtes un professionnel et vous avez besoin d'une formation ? Sensibilisation à
l'Intelligence Artificielle Voir le programme détaillé