Question

This code didn’t works as expected. I want to select all the posts that have the TAGS 561, 562, together or separately, but without any tag that is not present here->>> IN (561, 562)

 SELECT post_id_post
 FROM post_has_tags
 WHERE tags_id_tags IN (561, 562)
 HAVING COUNT(tags_id_tags) <= 2 

post_id_post        tags_id_tags    
600                    561  
600                    562  
600                    917  // 917 is not inside IN (561, 562)

But this code will output the post 600. It’s wrong, the correct output should be no results.

thanks

Answer 1

Try this:

select distinct p1.post_id_post from post_has_tags p1
where not exists (
  select * from post_has_tags p2
  where p1.post_id_post = p2.post_id_post and p2.tags_id_tags not in (561, 562)
)

I don’t want to be less than Phil, so I’m adding my fiddle too 🙂