mysql.py 文件源码

def compare_server_default(self, inspector_column,
                               metadata_column,
                               rendered_metadata_default,
                               rendered_inspector_default):
        # partially a workaround for SQLAlchemy issue #3023; if the
        # column were created without "NOT NULL", MySQL may have added
        # an implicit default of '0' which we need to skip
        if metadata_column.type._type_affinity is sqltypes.Integer and \
            inspector_column.primary_key and \
                not inspector_column.autoincrement and \
                not rendered_metadata_default and \
                rendered_inspector_default == "'0'":
            return False
        else:
            return rendered_inspector_default != rendered_metadata_default