Python mapper.column_attrs方法代码示例

# 需要导入模块: from sqlalchemy import mapper [as 别名]
# 或者: from sqlalchemy.mapper import column_attrs [as 别名]
def associate_with(cls, sqltype):
        """Associate this wrapper with all future mapped columns
        of the given type.

        This is a convenience method that calls
        ``associate_with_attribute`` automatically.

        .. warning::

           The listeners established by this method are *global*
           to all mappers, and are *not* garbage collected.   Only use
           :meth:`.associate_with` for types that are permanent to an
           application, not with ad-hoc types else this will cause unbounded
           growth in memory usage.

        """

        def listen_for_type(mapper, class_):
            for prop in mapper.column_attrs:
                if isinstance(prop.columns[0].type, sqltype):
                    cls.associate_with_attribute(getattr(class_, prop.key))

        event.listen(mapper, 'mapper_configured', listen_for_type) 

# 需要导入模块: from sqlalchemy import mapper [as 别名]
# 或者: from sqlalchemy.mapper import column_attrs [as 别名]
def associate_with(cls, sqltype):
        """Associate this wrapper with all future mapped columns
        of the given type.

        This is a convenience method that calls
        ``associate_with_attribute`` automatically.

        .. warning::

           The listeners established by this method are *global*
           to all mappers, and are *not* garbage collected.   Only use
           :meth:`.associate_with` for types that are permanent to an
           application, not with ad-hoc types else this will cause unbounded
           growth in memory usage.

        """

        def listen_for_type(mapper, class_):
            if mapper.non_primary:
                return
            for prop in mapper.column_attrs:
                if isinstance(prop.columns[0].type, sqltype):
                    cls.associate_with_attribute(getattr(class_, prop.key))

        event.listen(mapper, "mapper_configured", listen_for_type) 

# 需要导入模块: from sqlalchemy import mapper [as 别名]
# 或者: from sqlalchemy.mapper import column_attrs [as 别名]
def associate_with(cls, sqltype):
        """Associate this wrapper with all future mapped columns
        of the given type.

        This is a convenience method that calls
        ``associate_with_attribute`` automatically.

        .. warning::

           The listeners established by this method are *global*
           to all mappers, and are *not* garbage collected.   Only use
           :meth:`.associate_with` for types that are permanent to an
           application, not with ad-hoc types else this will cause unbounded
           growth in memory usage.

        """

        def listen_for_type(mapper, class_):
            if mapper.non_primary:
                return
            for prop in mapper.column_attrs:
                if isinstance(prop.columns[0].type, sqltype):
                    cls.associate_with_attribute(getattr(class_, prop.key))

        event.listen(mapper, 'mapper_configured', listen_for_type) 

# 需要导入模块: from sqlalchemy import mapper [as 别名]
# 或者: from sqlalchemy.mapper import column_attrs [as 别名]
def as_mutable(cls, sqltype):
        """Associate a SQL type with this mutable Python type.

        This establishes listeners that will detect ORM mappings against
        the given type, adding mutation event trackers to those mappings.

        The type is returned, unconditionally as an instance, so that
        :meth:`.as_mutable` can be used inline::

            Table('mytable', metadata,
                Column('id', Integer, primary_key=True),
                Column('data', MyMutableType.as_mutable(PickleType))
            )

        Note that the returned type is always an instance, even if a class
        is given, and that only columns which are declared specifically with
        that type instance receive additional instrumentation.

        To associate a particular mutable type with all occurrences of a
        particular type, use the :meth:`.Mutable.associate_with` classmethod
        of the particular :class:`.Mutable` subclass to establish a global
        association.

        .. warning::

           The listeners established by this method are *global*
           to all mappers, and are *not* garbage collected.   Only use
           :meth:`.as_mutable` for types that are permanent to an application,
           not with ad-hoc types else this will cause unbounded growth
           in memory usage.

        """
        sqltype = types.to_instance(sqltype)

        def listen_for_type(mapper, class_):
            for prop in mapper.column_attrs:
                if prop.columns[0].type is sqltype:
                    cls.associate_with_attribute(getattr(class_, prop.key))

        event.listen(mapper, 'mapper_configured', listen_for_type)

        return sqltype 

# 需要导入模块: from sqlalchemy import mapper [as 别名]
# 或者: from sqlalchemy.mapper import column_attrs [as 别名]
def as_mutable(cls, sqltype):
        """Associate a SQL type with this mutable Python type.

        This establishes listeners that will detect ORM mappings against
        the given type, adding mutation event trackers to those mappings.

        The type is returned, unconditionally as an instance, so that
        :meth:`.as_mutable` can be used inline::

            Table('mytable', metadata,
                Column('id', Integer, primary_key=True),
                Column('data', MyMutableType.as_mutable(PickleType))
            )

        Note that the returned type is always an instance, even if a class
        is given, and that only columns which are declared specifically with
        that type instance receive additional instrumentation.

        To associate a particular mutable type with all occurrences of a
        particular type, use the :meth:`.Mutable.associate_with` classmethod
        of the particular :class:`.Mutable` subclass to establish a global
        association.

        .. warning::

           The listeners established by this method are *global*
           to all mappers, and are *not* garbage collected.   Only use
           :meth:`.as_mutable` for types that are permanent to an application,
           not with ad-hoc types else this will cause unbounded growth
           in memory usage.

        """
        sqltype = types.to_instance(sqltype)

        # a SchemaType will be copied when the Column is copied,
        # and we'll lose our ability to link that type back to the original.
        # so track our original type w/ columns
        if isinstance(sqltype, SchemaEventTarget):
            @event.listens_for(sqltype, "before_parent_attach")
            def _add_column_memo(sqltyp, parent):
                parent.info['_ext_mutable_orig_type'] = sqltyp
            schema_event_check = True
        else:
            schema_event_check = False

        def listen_for_type(mapper, class_):
            for prop in mapper.column_attrs:
                if (
                        schema_event_check and
                        hasattr(prop.expression, 'info') and
                        prop.expression.info.get('_ext_mutable_orig_type')
                        is sqltype
                ) or (
                    prop.columns[0].type is sqltype
                ):
                    cls.associate_with_attribute(getattr(class_, prop.key))

        event.listen(mapper, 'mapper_configured', listen_for_type)

        return sqltype