php - Populate table data from databse table on selecting a particuar item from drop down list? -

i want populate table data database table "onchange" event dropdown list. dropdown list contains data table contains 1 column value. when user selects of item drop down list columns , values should displayed belong particular value of selected item drop down list.

below code display dropdown list.

<?php     include_once("session.php");     include_once("functions.php");     include_once("connection.php");      $employername=$_session["username"];     $sql = "select job_name job_info username=$employername";     $result = $conn->query($sql);  ?>  <div>     <select name="ddljobname">     <?php while($row=$result->fetch_assoc()){ ?>         <option value="<?= $row['job_name'] ?>"><?= $row['job_name'] ?>         </option>     <?php }?>     </select> </div> 

 <select name="ddljobname" id="getdata">     <?php while($row=$result->fetch_assoc()){ ?>         <option value="<?= $row['job_name'] ?>"><?= $row['job_name'] ?>         </option>     <?php }?>     </select> 

onchange function :

$('#getdata').change(function(){ var jobnum = $(this).val(); //call ajax  });