实际应用场景：数据去重--当多条记录主键相同或者多条记录完全一致时，只需要留下一条记录

delete from bal_acctbook_info
 where rowid not in (select min(rowid)
                       from bal_acctbook_info
                      where balance_id = '4012562452'
                        and op_time = '20171212111111');
https://www.cnblogs.com/whut-helin/p/8024860.html