code ignator update_batch error
<p>While using <code>update_batch</code> function for codeigniter batch update I get this error</p>

<blockquote>
  <p>Undefined index: admission_no</p>
</blockquote>

<p><a href="https://i.stack.imgur.com/X8EkZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/X8EkZ.png" alt="enter image description here"></a></p>

<pre><code>function test_update(){
    $updateArray = array();
    $elefee = $this-&gt;input-&gt;post('effe');
    $extra = $this-&gt;input-&gt;post('extra');
    $messfe = $this-&gt;input-&gt;post("messfee");
    $students = $this-&gt;Messmodel-&gt;get_each_student();

        foreach ($students as $row){
            $newdue = abs($row-&gt;amount - ($row-&gt;mess_fee + $row-&gt;ele_fee + $row-&gt;dues));
            $finaldays = ($row-&gt;messdays - $row-&gt;messcut) * $messfe;
            $messfee = $finaldays + $extra;
            $updateArray[]=array('admission_no'=&gt;$row-&gt;ADMISSION_NUMBER,'mess_fee' =&gt; $messfee);
        }

    $this-&gt;db-&gt;update_batch('mess',$updateArray,'admission_no');
}
</code></pre>

<p>this is my db snap
<a href="https://i.stack.imgur.com/b0nDb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/b0nDb.png" alt="enter image description here"></a></p>

<p>When i print update array I get this</p>

<p><a href="https://i.stack.imgur.com/TGdxW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TGdxW.png" alt="enter image description here"></a></p>