php - strpos always returning true -

my code return "true" whatever string tried bunch of thing return false... have no idea can fix this... code:

public function isblacklisted($string) {     $apis = mysql_connect("mysql.hostinger.fr", "mysql user", "testpass") or die(mysql_error());     mysql_select_db("u770656121_api", $apis);     $sql = "select * blacklist";     $result = mysql_query($sql, $apis);     while($row = mysql_fetch_array($result)) {         $username = $row['username'];         if (strpos($string,$username) !== 0) {             return true;             break;         } else {             return false;             break;         }     } } 

strpos returns false is not found, , 0 if in first position of string. sounds want do:

if (strpos($string,$username) !== false) { 

also, looping on db results, should return if found:

 while($row = mysql_fetch_array($result)) {     $username = $row['username'];     if (strpos($string,$username) !== false) {         return true;     }  }  return false; 

or, better:

$sql = "select * blacklist 'username' '%$username%'"; $result = mysql_query($sql, $apis); while($row = mysql_fetch_array($result)) {    if ($row['username']) return true; } 

making sure escape $username , ideally switching mysqli or pdo instead of using deprecated mysql statements.