how can i stop duplicate values from being shown? - php

Question

Ok, so I Have been trying to figure this out for 2 days with no real success
This is the code I have
$splash_list = '';
$splash_array = array();
$sql = "SELECT * FROM pm WHERE receiver='$username' OR sender='$username'";
$query = mysqli_query($db, $sql);
while($row = mysqli_fetch_array($query, MYSQLI_ASSOC)){
if($username == $row['sender']){
$otuser = array_push($splash_array, $row['receiver']);
$this_user = $row['sender'];
} else {
$otuser = array_push($splash_array, $row['sender']);
$this_user = $row['receiver'];
}
}
foreach($splash_array as $otuser){
$splash_list .= '<div>'.$otuser.'<br></div>';
}
The output is
otuser1
otuser1
otuser1
otuser2
otuser2
If any one can give me a pointer on how i'd go about
only outputting each value once like so
otuser1
otuser2
It'd be greatly appreciated :)

Answer 1

Well you could do SELECT DISTINCT ... (DISTINCT optimization docs)
But there's some other serious concerns with your code...
SELECT * is evil
mysql_* functions are deprecated
Your code is vulnerable to SQL injections
Look into using PHP's PDO for more help.
Your resulting code will look something like
$query = $db->prepare("
SELECT DISTINCT sender, receiver
FROM pm
WHERE receiver = :username
or sender = :username
");
$result = $query->execute(array("username" => $username));
Notice the documentation suggests you should use a colon like this → ":username" => $username. A little known goodie about PDO parameter binding is that the : is optional. Youpi!

Answer 2

I think DISTINCT would not work for this. Because DISTINCT will return unique combinations of sender and reciever, so ('otuser1', 'otuser2') and ('otuser2', 'otuser1') would be different.
Easiest solution:
array array_unique ( array $array [, int $sort_flags = SORT_STRING ] )
http://de2.php.net/manual/en/function.array-unique.php