1.查找表中多余的重復(fù)記錄，重復(fù)記錄是根據(jù)單個字段（name）來判斷
select * from lib
where name in (select name from lib group by name having count(name) > 1)2.刪除表中多余的重復(fù)記錄，重復(fù)記錄是根據(jù)單個字段（id）來判斷，只留有id最小的記錄
delete from lib
where name in (select name from (select name from lib group by name having count(name) > 1) as a)
and id not in (select min_id from (select min(id) as min_id from lib group by name having count(name)>1) as b)3.刪除表中多余的重復(fù)記錄（多個字段），只留有id最小的記錄
DELETE FROM lib WHERE (`name`, version) IN
(SELECT t.`name`, t.version FROM
(SELECT `name`, version FROM lib GROUP BY `name`, version HAVING count(1) > 1 ) t)
AND id NOT IN ( SELECT dt.minid FROM
(SELECT min(id) AS minid FROM lib GROUP BY `name`, version HAVING count(1) > 1 ) dt);參考：https://blog.csdn.net/JineD/article/details/126875291文章來源地址http://www.zghlxwxcb.cn/news/detail-543325.html
文章來源：http://www.zghlxwxcb.cn/news/detail-543325.html
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