Question

I have a forum and im looping through the replies to a thread, and for each instance its querying the members database for the users info.

I’d like to do it in one query if possible. What kind of sql join do I need for this?
Here’s my existing code:

$sql_result = mysql_query("SELECT * FROM forum_replies WHERE topic='$topic_id' AND del=0 ORDER BY date asc", $db); 
while($rs = mysql_fetch_array($sql_result))
{
   $sql_result2 = mysql_query("SELECT * FROM members WHERE id='$rs[author]'", $db);
   $rs2 = mysql_fetch_array($sql_result2);

Queries:

SELECT * FROM forum_replies WHERE topic='$topic_id' AND del=0 ORDER BY date asc
SELECT * FROM mobsters WHERE id='$rs[author]'"

Answer 1

I guess you are looking for something like this:

select * 
    from forum_replies as fr
    left join mobsters as m on m.id = fr.author
    where
        fr.topic = :topic_id
        and del = 0
    order by fr.date asc

You want to select the replies and the data of the author alongside with every row. :topic_id is the place for your topic ID (a notation used in PDO which you should look up and use instead of the mysql_ functions).

I have an important suggestion though: instead of select *, you should specify what you really want to return from your tables, what you really need.

For example:

select fr.id, fr.title, fr.date, m.id, m.nickname
    ...