The secret of 1>0

Hi all,

You might seen some MySQL statement likes below:

$sql="SELECT * FROM table WHERE 1>0";

Alright, so, what's the usage or secret behind of 1>0?
It's actually used when we have to check other condition after MySQL statement above, so our SQL statement will be likes below:

if($user!='')
  $sql.=" AND user='".$user."'";

So, 1>0 is actually used to enforce the SQL statement to be executed, as TRUE AND TRUE results TRUE.