How to delete duplicates on a MySQL table?

Question

I need to DELETE duplicated rows for specified sid on a MySQL table.

How can I do this with an SQL query?

Answer 1

This work for me to remove old records:

delete from table where id in 
(select min(e.id)
    from (select * from table) e 
    group by column1, column2
    having count(*) > 1
); 

You can replace min(e.id) to max(e.id) to remove newest records.