Question

Warning: mysql_fetch_array() expects parameter 1 to be resource, string given in C:\xampp\htdocs\test\index.php on line 19

 <?php
 $con = mysql_connect('localhost');
 if (!$con)
   {
   die('Could not connect: ' . mysql_error());
   }


 mysql_select_db("schedule", $con);

 $sql = "SELECT * FROM classes LIMIT 0,50\n";

 mysql_query($sql);

 IF (!$sql) {
   ECHO 'broken';
 };

 while($row = mysql_fetch_array($sql, MYSQL_BOTH))
   {
   echo $row['language'] . " " . $row['level'];
   echo "<br />";
   }

 mysql_close($con);
 ?> 

why? the query works in phpmyadmin

Answer 1

Your parameter to mysql_fetch_array() function is your SQL statement string. This is what your warning say. You should first use
$res = mysql_query($sql);
and pass $res as parameter to mysql_fetch_array()