程序師世界是廣大編程愛好者互助、分享、學習的平台,程序師世界有你更精彩!
首頁
編程語言
C語言|JAVA編程
Python編程
網頁編程
ASP編程|PHP編程
JSP編程
數據庫知識
MYSQL數據庫|SqlServer數據庫
Oracle數據庫|DB2數據庫
 程式師世界 >> 數據庫知識 >> MYSQL數據庫 >> MySQL綜合教程 >> Mysql刪除重復的數據 Mysql數據去重復,mysql數據

Mysql刪除重復的數據 Mysql數據去重復,mysql數據

編輯:MySQL綜合教程

Mysql刪除重復的數據 Mysql數據去重復,mysql數據


MySQL數據庫中查詢重復數據

select * from employee group by emp_name having count (*)>1;

Mysql  查詢可以刪除的重復數據

select t1.* from employee t1 where (t1.emp_name) in (select t4.emp_name from (select t2.emp_name from employee t2 group by t2.emp_name having count(*)>1) t4) and t1.emp_id not in (select t5.emp_id from (select min(t3.emp_id) as emp_id from employee t3 group by t3.emp_name having count(*)>1) t5);

Mysql  刪除重復的數據

delete t1 from employee t1 where (t1.emp_name) in (select t4.emp_name from (select t2.emp_name from employee t2 group by t2.emp_name having count(*)>1) t4) and t1.emp_id not in (select t5.emp_id from (select min(t3.emp_id) as emp_id from employee t3 group by t3.emp_name having count(*)>1) t5);

  1. 上一頁:
  2. 下一頁:
Copyright © 程式師世界 All Rights Reserved