Can't specify target table for update, delete query in mysql

Question

I want to do what seems like a simple delete in mysql but am having some trouble. I want to do this:

delete from table where col_name not in (select distinct col_name from table);

This table does not have a unique key. When I try this, I get the error:

You can't specify target table for update in from clause; ErrorNr. 1093

mysql community 5.1

Is there a way i can save the output from this query ->

select distinct col_name from table;

into temp. table and use it in the delete query?

Answer 1

You must use an alias.

delete from table where col_name not in (select a.col_name from (select distinct col_name from table) a);

It should work.

Edit : sorry, I misunderstood the question, and only focus on the SQL Error. The probleme to delete duplicate line with no unique key isn't answered by the above request.

Answer 2

the answer by @Molochdaa which is accepted is wrong

Explanation. suppose this is the table

col_name |  value
------------------
east     |  10
west     |  15
east     |  10
west     |  15
north    |  5
east     |  10
north    |  5

select distinct col_name from table_name gives:

col_name
------------------
east     
west     
north    

now when you write delete from table where col_name not in ( ... )then no row will be returned as every column is in the returned list

The correct answer would be (suggested by @jeffery_the_wind)

delete from table where col_name in (
   select a.col_name from (
      select col_name from table group by col_name having count(*)>1
   ) a
)

Another answer which is more simple

delete from table_name
       where rowid not in ( select min(rowid) 
                            from Table_name
                            group by column1..,column2,...column3..)