sql语句查重

我的想法是比较count（列）和count（distinct 列）是否相等。不知道大家有没有更好的方法。

你的图中post_content全一样，post_title有两种，这算不算重复呀？我按post_content重复就查找出来。查重：select post_content,post_title from wp_posts group by post_content having count(post_content)>1删除要先将数据查询到临时表中，然后将原表清空，在追加回来。

使用临时表求出重复记录select userid from t_name group by userid having count(*) > 1求出不重复记录select distinct * into #a1 from t_name where userid in select userid from t_name group by userid having count(*) > 1删除重复记录从#a1取出不重复记录

SELECT *, count(*) AS CCCFROM 表明GROUP BY 字段ORDER BY CCC DESC

你表里就俩字段的话不太好弄，如果有第三个字段select post_content,post_title from wp_posts group by post_content,post_title having count(*)>1先看看有多少重复的假设你表中还有id的一个字段select min(id),post_content,post_title from wp_posts group by post_content,post_title这些选出来后你看看这些是否可以不删除然后delete from wp_posts where id not in (select min(id) from wp_posts group by post_content,post_title) 没懂你补充的那句话是什么意思 那就是你上边的图里，你要把第一条和第三条删除呗？还有你问的那个字符集的问题，是瑞典，不是雅典

select * from table1 b where bill_id=(select top 1 bill_id from table1 a where exists(select top 1 column1 from table1 where column1=lumn1 group by column1 having count(*)>1 order by column1) and lumn1=lumn1) order by column1SQL语句查询有部份字段重复的第一条数据