MySQL - 随笔分类 - Helsing

mysql error:You can't specify target table for update in FROM clause

摘要：mysql中You can't specify target table for update in FROM clause错误的意思是说，不能先select出同一表中的某些值，再update这个表(在同一语句中)。例如下面这个sql：代码如下: delete from tbl where id 阅读全文

posted @ 2016-09-21 13:38 Helsing 阅读(180) 评论(0) 推荐(0)

查询及删除重复记录的SQL语句

摘要：1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断 select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 阅读全文

posted @ 2016-09-21 13:35 Helsing 阅读(966) 评论(0) 推荐(0)

随笔分类 - MySQL

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