如何从两个表中提取帖子的用户信息？

I have two tables, a "users" and "updates" table. I want to grab these values from the tables:

id, username - from the "users" table message, createdOn - from the "updates" table

I need to grab these values for a specified user and friends of the user. I have already created an array containing all friends id's that would look like this:

array(1,3,7,21,45);

I need a query that will select all of the updates with an matching the previous array. The "updates" table also has a column "uid" which defines the user who posted the update. This is what I have so far:

$updates = "SELECT users.id, users.username, updates.message, updates.createdOn FROM users, updates WHERE updates.uid = '". $_COOKIE['id'] ."' ". $friendsNews ." ORDER BY updates.createdOn DESC LIMIT 0, 10";
$updates = mysql_query( $updates );

This isn't working for me though, I created a foreach loop that also creates an or statement which is inserted into the query "$friendsNews" that looks like this:

foreach( $myFriends as $fid ) {
     $friendsNews .= " OR updates.uid = '". $fid ."'";
}

Once the entire query compiles the result of the query is this:

SELECT users.id, users.username, updates.message, updates.createdOn FROM users, updates WHERE updates.uid = '1' OR updates.uid = '2' OR updates.uid = '3' ORDER BY updates.createdOn DESC LIMIT 0, 10

If someone could help I would really appreciate it, I'm not very experienced with SQL join statements. Thanks!

Try

$sql = "SELECT users.id, users.username, updates.message, updates.createdOn, ". 
" updates.message, updates.createdOn ".
" FROM users ".
" INNER JOIN updates ON updates.uid = users.id ".
" WHERE  ".
" updates.uid  IN ( ".implode(', ', $myFriends)." )";

I think that if you want to grab all updates for the users specified in the ids array, the simplest way would be to use a sql JOIN and an IN clause

select users.id, users.username, u1.message, u1.createdOn
from updates as u1
join users as u2 on u2.id = u1.uid
where u1.uid in(1,3,7,21,45)
order by u1.createdOn desc limit 0, 10;

Try this

if (in_array($_COOKIE['id'], $myFriends)) {
   $flist = implode(',', $myFriends) 
}else{
   $flist =  $_COOKIE['id'].','.implode(',', $myFriends);   //if $_COOKIE['id'] is differed.....
}

$sql = "SELECT users.id, users.username, updates.message, updates.createdOn,          
          updates.message, updates.createdOn FROM users INNER JOIN updates
              updates.uid = users.id WHERE updates.uid  IN ( ".$flist." )";

Help for Logged user is differed.....