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mysql 剔除重复数据

直接拿1楼的来改吧, delete from zhszty_ebook where id not in( select * from (select max(id) from zhszty_ebook group by url ) as tmp);------------mysql有个特性,对于表进行修改,删除操作,子查询不能和外层的查询的表一样,所以在加...

//去除重复的数据 如果是重复的只显示1个 select distinct d_name from tbl_vod --下面是查出重复的记录 select d_name from tbl_vod minus select distinct d_name from tbl_vod

应该是这么写的,你备份数据之后试试 delete from cars where id not in( select id from (select id,max(pici) from cars group by xinghao)a )

其实你会用英文搜索的话。可以很方便在stack overflow上 找到相关的信息 真的学CS的就不要用百度了 用google你会发现一个不一样的世界的 随便贴一个 sql - How can I remove duplicate rows? 稍微讲一下其中一个思路(里面有很多很好的答案 你可...

例如: id name value 1 a pp 2 a pp 3 b iii 4 b pp 5 b pp 6 c pp 7 c pp 8 c iii id是主键 要求得到这样的结果 id name value 1 a pp 3 b iii 4 b pp 6 c pp 8 c iii 方法1 delete YourTable where [id] not in ( select max([id]) from Your...

不建议直接删除,养成良好的习惯(删除更麻烦),以下是将去重后的数据转移到另一张表代码: Insert into 表名(列名)select distinct 列名 from 表名 你可以按照去重的思路,删除重复数据

假如我有一张表, 数据在某一个字段有重复(比如我现在的ID重复了) 那么我使用: SELECT id,COUNT(*) FROM table GROUP BY id HAVING COUNT(*) > 1; 语句 意思: 从读下来是 查询id,并且统计行数 数据来自 table表 按照id列进行分组(如果我们...

删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录 delete from people where peopleName in (select peopleName from people group by peopleName having count(peopleName) > 1) and peopleId not in...

列出要保留的记录ID,可以把这个结果写到一个临时表t1中: SELECT MAX(id) AS max_id FROM pedigree GROUP BY number 然后:DELETE FROM pedigree WHERE id NOT IN (SELECT id FROM t1) 也就是:delete from pedigree where id not in(select * ...

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