如果似乎不起作用

Question

Right, I am going to get straight into this.

I am building an Add Friend button. if the person is in the same row as the session (person logged on), it shouldn't echo Add Friend.

If the name of the person is in the row, and the page id doesn't match the session id, it should echo a button. But there are two rows the name might be in and I use a simple '||' to seperate. But my if doesn't work. It returns 'Add Friend' despite the fact that it is in the last. I deleted the second 'OR' factor and just used one statement and it worked.

RelatedUser and RelatingUser are the two possible fields that page id result might be in.

My code is below:

    $session_username_query = mysql_query("SELECT * FROM users WHERE username='{$_SESSION['user_login']}'");
    $session_username_assoc = mysql_fetch_assoc($session_username_query);
    $session_username = $session_username_assoc['username']; //the person who is logged in

    $profile_view_query = mysql_query("SELECT * FROM friend WHERE RelatedUser='$session_username' OR RelatingUser='$session_username'");
     $profile_view_assoc = mysql_fetch_assoc($profile_view_query);
     $related = $profile_view_assoc['RelatedUser'];
     $relating = $profile_view_assoc['RelatingUser']; 

      if ($username != $relating && $_GET['id'] != $session_username_assoc['id'] || $username != $related && $_GET['id'] != $session_username_assoc['id']) {
 $addAsFriend = '<input type="submit" name="addfriend" value="Add Friend">';
    echo $addAsFriend;
    } 

Answer 1

I think removing the OR operand (||) would give you the desired result.

if (
    $username != $relating &&
    $username != $related &&
    $_GET['id'] != $session_username_assoc['id']
) {
    $addAsFriend = '<input type="submit" name="addfriend" value="Add Friend">';
    echo $addAsFriend;
} 

Edit

Perhaps I misread your question. Does this work instead?

if (
    ($username != $relating || $username != $related) &&
    $_GET['id'] != $session_username_assoc['id']
) {
    $addAsFriend = '<input type="submit" name="addfriend" value="Add Friend">';
    echo $addAsFriend;
}