I want to print binary tree (Below Image) in php from database value 
And above is my database table structure 
Here is what I tried, In this code I want to display binary tree of user id PX100
<?php
include 'db_connect.php';
$user_id = 'PX100';
$select_right_tree = $con->prepare("SELECT * FROM tbl_user_postion WHERE user_id=:user_id");
$select_right_tree->bindParam(":user_id", $user_id);
$select_right_tree->execute();
$fetch_right_tree = $select_right_tree->fetch(PDO::FETCH_ASSOC);
$ex_pos_right = $fetch_right_tree['pos_right'];
$ex_pos_left = $fetch_right_tree['pos_left'];
function right_part($pos_right) {
if(!empty($pos_right)) {
$select_left_tree = $con->prepare("SELECT pos_right, pos_left FROM tbl_user_postion WHERE user_id=:user_id");
$select_left_tree->bindParam(":user_id", $pos_right);
$select_left_tree->execute();
$fetch_left_tree = $select_left_tree->fetch(PDO::FETCH_ASSOC);
$user_right = $fetch_left_tree['pos_right'];
$user_left = $fetch_left_tree['pos_left'];
return array($user_right, $user_left);
if(!empty($user_right)) {
right_part($user_right);
}
if(!empty($user_left)) {
left_part($user_left);
}
}
}
function left_part($pos_left) {
if(!empty($pos_left)) {
$select_left_tree = $con->prepare("SELECT pos_right, pos_left FROM tbl_user_postion WHERE user_id=:user_id");
$select_left_tree->bindParam(":user_id", $pos_left);
$select_left_tree->execute();
$fetch_left_tree = $select_left_tree->fetch(PDO::FETCH_ASSOC);
$user_right = $fetch_left_tree['pos_right'];
$user_left = $fetch_left_tree['pos_left'];
return array($user_right, $user_left);
if(!empty($user_left)) {
left_part($user_left);
}
if(!empty($user_right)) {
right_part($user_right);
}
}
}
?>
<div class="tree">
<ul>
<li>
<a href="#"><img src="image/user.png" ><br/><?php echo $user_id; ?></a>
<ul>
<li>
<a href="#"><img src="image/user.png"><br/><?php echo $ex_pos_right; ?></a>
<?php
if(!empty($ex_pos_right))
{
list($pos_right1, $pos_left1) = right_part($ex_pos_right);
?>
<ul>
<li> <a href="#"><img src="image/user.png"><br/><?php echo $pos_right1; ?></a> </li>
<li> <a href="#"><img src="image/user.png"><br/><?php echo $pos_left1; ?></a> </li>
</ul>
<?php
}
?>
</li>
<li>
<a href="#"><img src="image/user.png"><br/><?php echo $ex_pos_left; ?></a>
<?php
if(!empty($ex_pos_left))
{
list($pos_right2, $pos_left2) = left_part($ex_pos_left);
?>
<ul>
<li> <a href="#"><img src="image/user.png"><br/><?php echo $pos_right2; ?></a> </li>
<li> <a href="#"><img src="image/user.png"><br/><?php echo $pos_left2; ?></a> </li>
</ul>
<?php
}
?>
</li>
</ul>
</li>
</ul>
</div>Output of the above code is Here,
From database table, PX103 is a parent of PX108 and PX110, PX105 is parent of PX107 and PX111 , PX106 is parent of PX109. But PX108, PX110, PX107, PX111 and PX109 are not displaying in tree.
Please help me to sort out this problem. Thankyou.
