Question

I have friends table where there are stored two friends’ IDs. When I query, let’s say my friends, is there an easy way to get my friends’ names from users table? I use PHP and MySQL and the tables are not connected by foreign key but I think I can connect them (using Navicat).

My query:

session_start();
if(isset($_SESSION['valid_user']))
    {
        $currentuser= $_SESSION['valid_user'];
    }


$friendships= mysql_query("SELECT * FROM friends WHERE Person1 = '$currentuser' OR Person2 = '$currentuser' ");
while($row = mysql_fetch_assoc($friendsips))
    {
        if ($row['Person1'] == $currentuser) echo $row['Person2']; // quering the users name from here is hard and long thing to do
        if ($row['Person2'] == $currentuser) echo $row['Person1'];
    }

friends(friendshipID, Person1, Person2)

users(ID, name, surname)

Answer 1

Assuming the table structure is :

Users:
userid , name

Friends:
friendship_id , userid_1 , userid_2

SELECT name 
FROM Friends F JOIN Users U ON (F.userid_2 = U.userid) 
WHERE userid_1 = X

Edit:
If you want to get both names you can use this.

SELECT 
  U1.name as name1 , U2.name as name2
FROM 
 Friends F 
 JOIN Users U1 ON (F.userid_1 = U1.userid) 
 JOIN Users U2 ON (F.userid_2 = U2.userid) 
WHERE 
 userid_1 = X

You can adjust the where clause to query on either user ids.