如何将PHP递归函数转换或写入mysql递归存储过程

Question

问题：

如何将PHP递归函数转换或写入mysql递归存储过程？

问题：

下面的php递归占用了太多的加载时间来获取父子节点。所以请告诉我如何通过在mysql中编写存储过程来提高性能。

我的PHP代码：

  <?php
function display_children($parent, $level) 
{
    $con=mysqli_connect("localhost","root","","testing_purpose");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }
    $result = mysqli_query($con,"SELECT a.parent,a.id, a.label, a.link, Deriv1.Count FROM `menu` a  LEFT OUTER JOIN (SELECT parent, COUNT(*) AS Count FROM `menu` GROUP BY parent) Deriv1 ON a.id = Deriv1.parent WHERE a.parent=" . $parent);
    echo "<ul class='menu'>";
    while ($row = mysqli_fetch_assoc($result)) 
    {
        if ($row['Count'] > 0)
        {
            echo "<li style='display:none;' id='" . $row['parent'] . "' onclick=id_func('" . $row['id'] . "')>" . $row['label'];
            display_children($row['id'], $level + 1);
            echo "</li>";
        } 
        elseif ($row['Count']==0) 
        {
            echo "<li style='display:none;' id='" . $row['parent'] . "' onclick=id_func('" . $row['id'] . "')>" . $row['label'] . "</li>";
        } else;
    }
    echo "</ul>";
    mysqli_close($con);
}
display_children(0,1);
?>

注意：

我是mysql存储过程的初学者