Mysql deletes duplicate data. Mysql deletes duplicate data.
Query duplicate data in the MySQL database
Select * from employee group by emp_name having count (*)> 1;
Mysql queries repeated data that can be deleted
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 deletes duplicate data
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 );