Merging data from two different data sets (Facebook & MySQL)

Question

I'm wondering if this is the best way to tackle this issue. I am merging a Facebook users friends data, (from facebook - returns a multi array) with the votes from the users in that list that voted (from MySQL).

This is how I accomplished this. I'm a junior developer and looking for help on making my code as optimized as possible.

public function getFriendVotes(){
    global $facebook;

    // Get The users friends that use this app from facebook
    $friends = $facebook->api_client->fql_query(
      "SELECT uid, first_name, last_name
        FROM user
        WHERE uid IN (SELECT uid2 FROM friend WHERE uid1=$this->user)"
    );

    // Create an array of just the ids
    foreach($friends as $friend){
      $userids[] = $friend['uid'];
    }

    // Create a string of these ids
    $idstring = implode(",", $userids);

    // Get the votes from only the users in that list that voted
    $result = $this->db->query(
      "SELECT vote, userid FROM user_votes WHERE userid IN ($idstring)"
    );

    // Create a new result set (multi array).  Include the data from the first
    // Facebook query, but include only those who voted and append their votes
    // to the data
    $row = $result->fetch_assoc();
    foreach($friends as $friend){
      if($row['userid'] == $friend['uid']){
        $return[$count] = $friend;
        $return[$count]['vote'] = $row['vote'];
        $row = $result->fetch_assoc();
        $count++;
      }
    }
    return $return;
}

Answer 1

I asume that fql_query does support mysql syntax and it would be more efficient to use LEFT JOIN instead creatig extra query, here is my version of your code:

public function getFriendVotes(){
    global $facebook;

    // Get The users friends that use this app from facebook
    $friends = $facebook->api_client->fql_query("
        SELECT DISTINCT u.uid,u.first_name,u.last_name 
        FROM user AS u 
        LEFT JOIN friend AS f ON uid=uid2 
        WHERE f.uid1='{$this->user}'
    ");
    $arrayUsers = array();
    // Create an array of just the ids
    foreach($friends as $v){
        $arrayUsers[$friend['uid']] = $v;
    }
    unset($friends);

    // Create a string of these ids
    $idstring = implode(",", array_keys($arrayUsers));

    // Get the votes from only the users in that list that voted
    $result = $this->db->query(
      "SELECT vote, userid FROM user_votes WHERE userid IN ({$idstring})"
    );

    $result = array();
    // Create a new result set (multi array).  Include the data from the first
    // Facebook query, but include only those who voted and append their votes
    // to the data
    while($v = $result->fetch_assoc())
    {
        if(isset($arrayUsers[$v['userid']])
        {

            $arrayUsers[$v['userid']] = $v['vote'];

            $result[] = $arrayUsers[$v['userid']];

            unset($arrayUsers[$v['userid']], $v);
        }
    }

    return $return;
}