Apply array to data?

[Cultureshock]

How would I check a mysql table for each selection in an array?

for instance, if I have one table that has all of your 'friends,' how would I get all of the 'posts' made by ONLY your friends?

i.e.

 

table 1

You, friendid

 

table 2

friendid, content

 

I'd be happy to elaborate if need be.

[RussellReal]

I have NO idea if this works but I'd assume it does

 

SELECT * FROM posts WHERE friendid IN (SELECT friendid FROM friends)

 

if not you'd hafta do something like this:

 

<?php
  $r = mysql_query("SELECT friendid FROM friends");
  $friends = '(';
  $loop = 0;
  while ($row = mysql_fetch_assoc($r)) {
    if ($loop++ >= 1) $friends .= ',';
    $friends .= $row['friendid'];
  }
  $friends .= ')';
  $q = mysql_query("SELECT * FROM posts WHERE userid IN {$friends}");
?>