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
原文：https://www.cnblogs.com/qdck/p/10847749.html