mysql 查詢并删除重複的記錄

1.查詢重複的使用者名記錄

select user_name,count(*) as count from user group by user_name having count>1;
           

2.查找表中全部重複的記錄

Select * From 表 Where 重複字段 In (Select 重複字段 From 表 Group By 重複字段 Having Count(*)>1)
           

3.過濾重複記錄隻顯示一條

Select * From Table Where ID In (Select Max(ID) From Table Group By Title)
           

4.删除重複的記錄 儲存最小的

Delete Table Where ID Not In (Select Max(ID) From Table Group By Title)