Question

I need to remove rows where there is a duplicate link column from a table. I’m trying to run:

delete from resultitem 
       where id in (select r.id 
                    from resultitem r 
                    group by r.link
                    having count(r.id) >1);

But getting an error:

ERROR 1093 (HY000): You can't specify target table 'resultitem' for update in FROM clause

Is this possible to remove rows by subquery in MySQL without a temporary table?
Please advise.

Answer 1

This should delete all but the lowest id per link:

delete  ri1
from    resultitem as ri1
inner join
        resultitem as ri2
on      ri1.link = ri2.link
        and ri1.id > ri2.id

Live example at SQL Fiddle.

To remove all duplicate links, leaving none of the duplicates behind, remove the and ri1.id > ri2.id.