JSON编码SQL查询数据问题

我不明白为什么会返回空方括号。我实际上要做的是从一个href动态更新一个div。

<?php

$con=mysqli_connect("localhost","ee2800","secret","ee2800");
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
else{
    echo "connected";
}
 $select = mysql_query('SELECT * FROM Songs');
 $rows=array();
 While($row=mysql_fetch_array($select))
 {
  $rows[] = $row;   
 }
 echo json_encode($rows);

?>