#### mysql 同表两列值互换 // 假设表 table_test 字段有 id、start_at 、end_at，其中start_at ，跟 end_at的值搞返了，需要执行迁移修复 ``` update table_test as a, table_test as b set a.start_at = b.end_at, a.end_at = b.start_at where a.id = b.id AND a.start_at > a.end_at; ```