Dropdown list for reporting hierarchy data - php

Question

I have two tables reporting,employee_details
reporting contains suprvisor_id,subordinate_id fields which are emp_id in employee_details table .And reporting table contains three levels (supervisors->subordinates->subordinates->employees) and i want to show this data as dropdown by fetching name from employee_details table, as hierarchy .so please help me is there any way to do it?

Answer 1

You defititly need to get the hole tree in an array if you want to display it. And this is a little bit tricky.
I think you arent't really shure how many levels you have in tree.
So the simplest way is the following but in big trees it have a bad performance. When the tree grows really big you need to check other technics.
The following is fast written, not tested an could have some bugs. But I post it to show you a possible solution:
<?php
class tree {
private $level = 0;
public function getChildsRecoursive($parentid=0,$recoursive=false) {
// you would have your own db object... please replace this...
$db->select("select * from reporting r JOIN employee_details d ON(r.subordinate_id=d.emp_id) where supervisor_id='$parentid' ORDER BY d.name");
$r = array();
while($data = $db->fetchArray()) {
$sid = $data['supervisor_id'];
$cid = $data['subordinate_id'];
if($recoursive) {
$this->level++;
$data['level'] = $this->level;
$data['childs'] = $this->getChildsRecoursive($cid, true);
$this->level--;
}
$r[] = $data;
}
return $r;
}
public function getDropdown() {
// I suspect the top Level have a supervisor_id = 0
$data = $this->getChildsRecoursive(0,true);
// you can do a print_r($data) here to see if the results are correct
$r = "<select>";
foreach($data as $d) {
$r .= $this->getOptionsRecoursive($d);
}
$r .= "</select>";
return $r;
}
public function getOptionsRecoursive($data) {
$r = "<option>";
for($i=0;$i<$data['level'];$i++) {
$r .= " ";
}
$r .= $data['name'];
$r .= "</option>\n";
if(isset($data['childs'])) {
foreach($data['childs'] as $c) {
$r .= $this->getOptionsRecoursive($c);
}
}
return $r;
}
}
?>
Hope it helps to understand. (Please recognize that this will cause many queries depending on how big your tree is).
To Start you need to do
$tree = new tree();
echo $tree->getDropdown();