mysql DELETE与另一个表的字段检查

Question

Good morning all, happy thursday morning. I wish I could have done this by myself but since I'm not a master in MySQL statements (yet) and I got lost in this DELETE query, here it goes...

I have to do a simple DELETE query like this, (deleting a comment by its id)

DELETE FROM mya_news_comments WHERE comment_id='".$_GET['comment_id']."'";

but at the same time, to prevent people deleting comments throughout the website i need to ensure that the person deleting this comment is who it is supposed to be (in our case, an artist).

I have another table mya_news which has among the fields news_id , artist_id In mya_news_comments I also have a field called news_id

So I need to check that I delete the comment_id of the particular artist, not of other artist. Basically i need to cross-check if the news_id field from mya_news_comments checks out with a field with same news_id from mya_news , and artist_id from mya_news is equal to $_id (which holds my artist_id )

I'm really stuck here. I'd be glad to give more details if needed.

Thanks.

Answer 1

DELETE mya_news_comments
FROM   mya_news_comments
WHERE  mya_news_comments.comment_id = (SELECT [another_table].comment_id WHERE [cond])
   AND mya_news.artist_id = (SELECT [another_table].artist_id WHERE [cond]);

Answer 2

You can join tables in DELETE statements just like you can in SELECT statements:

DELETE mya_news_comments
FROM   mya_news_comments JOIN mya_news USING (news_id)
WHERE  mya_news_comments.comment_id = ?
   AND mya_news.artist_id = ?