Searching from comma separated value

Question

This is one of those \'oh my god\' moments.

The previous programmer in our company has left behind a badly-coded application using PHP and MySQL.

One example

Answer 1

$a = '123,456,789';
$a_array = explode(",",trim($a));
if(in_array('456',$a_array))
{
  echo 'exist';
} else echo 'not exist';