Update Query Doesnt work ?

Question

Hello,

These are my table structures

tblcomment
- - - - - - - - - - - - -
comment_id
content_id
user_id
picture_id
comment
comment_time

tblpictures
- - - - - - - - - - - - -
content_id
title
picture_id

I am trying to update the content_id field on pictures using this but it doesnt seem to work ?

UPDATE `comments`
SET 
comments.content_id = pictures.content_id
WHERE
comments.picture_id = pictures.picture_id

I get this error

1054 - Unknown column 'pictures.picture_id' in 'where clause'

Answer 1

UPDATE comments, pictures SET ...