<?php

function get_employees_by_hierarchy( $_employee_id = 0,$_depth = 0,$_org_array = array() ) {
    if ( $this->org_depth < $_depth ) {
        $this->org_depth = $_depth;
    }

    $_depth++;
    $_query = "SELECT * FROM employees WHERE ";
    if ( !$_employee_id ) {
        $_query .= "employee_manager_id IS NULL OR employee_manager_id = 0";
    } else {
        $_query .= "employee_manager_id = " . $this->dbh->quoteSmart( $_employee_id );
    }

    $_result = $this->query( $_query );

    while ( $_row = $_result->fetchRow() ) {
        $_row['depth'] = $_depth;
        array_push( $_org_array, $_row );
        $_org_array = $this->get_employees_by_hierarchy(
                        $_row['employee_manager_id'],
                        $_depth,
                        $_org_array
                        );
    }

    return $_org_array;
}

?>