ops.py 文件源码

def batch_alter_column(
        cls, operations, column_name,
        nullable=None,
        server_default=False,
        new_column_name=None,
        type_=None,
        existing_type=None,
        existing_server_default=False,
        existing_nullable=None,
        **kw
    ):
        """Issue an "alter column" instruction using the current
        batch migration context.

        .. seealso::

            :meth:`.Operations.add_column`

        """
        alt = cls(
            operations.impl.table_name, column_name,
            schema=operations.impl.schema,
            existing_type=existing_type,
            existing_server_default=existing_server_default,
            existing_nullable=existing_nullable,
            modify_name=new_column_name,
            modify_type=type_,
            modify_server_default=server_default,
            modify_nullable=nullable,
            **kw
        )

        return operations.invoke(alt)