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

delete p from 
product p
inner join (
    select max(id) as id, url from product 
    group by url 
    having count(*) > 1
) unik on unik.url = p.url and unik.id != p.id;