MYSQLI Error on 3.7

[aggiefan]

I had developed a pick 'em contest that worked great on 3.6.8. We just upgraded to 3.7 and I'm "cleaning up the errors" and found that my MYSQLI queries don't run (they return errors. Here's an example. Can somebody tell me what's wrong?

Error:

Warning: mysqli_query() expects at least 2 parameters, 1 given in [path]\vbcontest.php on line 2347

Code:

PHP Code:

$query_user = "SELECT game1, game2, game3, game4, game5, game6, game7, game8, game9, game10, game11, game12, game13, game14, game15 FROM " . TABLE_PREFIX . "vbcontest_picks WHERE contestname = '$contestname' AND weekid = '$week' AND userid ='$userid'"; 


PHP Code:

$result_user  = mysqli_query($query_user);