Question

It’s a bit difficult getting my problem into a short form, so I apologise if the title doesn’t make sense.

Anyway, here is the problem:

 $query = '
  SELECT issues.*, comments.author AS commentauthor, favorites.userid AS favorited FROM issues
  LEFT JOIN comments ON comments.issue = issues.id AND comments.when_posted = issues.when_updated
  LEFT JOIN favorites ON favorites.ticketid = issues.id AND favorites.userid = \'' . $_SESSION['uid'] . '\'
  ' . $whereclause . '
  ORDER BY issues.when_updated ' . $order;

Don’t mind the fact that it’s PHP as I am not asking for PHP help.

The query retrieves a bunch of issues, and what I’m wishing to do is obtain the row count of favorites that have favorites.ticketid matching issues.id. My use of LEFT JOIN favorites is not to get what I’ve just mentioned, but instead to obtain whether the client has favourited the issue, thus the part favorites.userid AS favorited.

I have tried doing the following: (all at once, I’m putting this in bulleted form for readibility)

• duplicating the existing LEFT JOIN favorites and removing the user id check from the duplicate
• adding , COUNT(favorites.ticketid) AS favoritescount to the SELECT section
• adding AS favorited to the original LEFT JOIN as well as changing favorites.userid to favorited.userid

With that attempt, my query ends up returning only one row.

Answer 1

SELECT issues.*,
       comments.author AS commentauthor,
       favorites.userid AS favorited,
       (
           SELECT COUNT(favorites.id)
           FROM favorites
           WHERE ticketid = issues.id
       ) AS numfavorites
FROM issues
LEFT JOIN comments
    ON comments.issue = issues.id
    AND comments.when_posted = issues.when_updated
LEFT JOIN favorites
    ON favorites.ticketid = issues.id
    AND favorites.userid = ?uid

That should work, I’m just using a subquery to get number of favourites