Remove duplicate rows in MySQL

Question

I have a table with the following fields:

id (Unique)
url (Unique)
title
company
site_id

Now, I need to remove rows having same titl

Answer 1

MySQL has restrictions about referring to the table you are deleting from. You can work around that with a temporary table, like:

create temporary table tmpTable (id int);

insert  into tmpTable
        (id)
select  id
from    YourTable yt
where   exists
        (
        select  *
        from    YourTabe yt2
        where   yt2.title = yt.title
                and yt2.company = yt.company
                and yt2.site_id = yt.site_id
                and yt2.id > yt.id
        );

delete  
from    YourTable
where   ID in (select id from tmpTable);

From Kostanos' suggestion in the comments:
The only slow query above is DELETE, for cases where you have a very large database. This query could be faster:

DELETE FROM YourTable USING YourTable, tmpTable WHERE YourTable.id=tmpTable.id