migrations.py 文件源码

def rename_link_table(self):
        old_table_name = 'requirement_deferred_actions__deferredaction_requirements'
        new_table_name = 'deferredaction_requirement'

        # Rename table itself
        self.schedule('alter', op.rename_table, old_table_name, new_table_name)

        # Rename of foreign key names
        for old_name, other_table_name in [
                ('deferredaction_requirements_fk', 'deferredaction'),
                ('requirement_deferred_actions_fk', 'requirement') ]:
            column_name = '%s_id' % other_table_name
            new_name = fk_name(new_table_name, column_name, other_table_name)
            self.schedule('drop_fk', op.drop_constraint, old_name, old_table_name)
            self.schedule('create_fk', op.create_foreign_key, new_name, new_table_name, other_table_name, [column_name], ['id'])

        # Primary keys are renamed according to new naming convention - in this case the table too
        self.rename_pk(new_table_name, ['deferredaction_id', 'requirement_id'], old_table_name=old_table_name)