Question

The following is a mySQL query containing the initial query followed by some additional criteria.

mysql_query("SELECT * FROM electors WHERE telephone > 0 AND last_known_voting_intention = 'P' OR last_known_voting_intention = 'A'");

I want to pass the additional criteria from another page and included in a PHP variable.

$criteria = "AND last_known_voting_intention = 'P' OR last_known_voting_intention = 'A'";

How do I then include that in the mySQL query.

mysql_query("SELECT * FROM electors WHERE telephone > 0 $criteria");

mysql_query("SELECT * FROM electors WHERE telephone > 0 ".$criteria);

These 2 do not appear to work.

Answer 1

Your original query looks like it should to work, but I wouldn’t be surprised if it’s one of PHP’s mysteries.

What you could do is this:

$sql = "SELECT * FROM electors WHERE telephone > 0";
$criteria = " AND last_known_voting_intention = 'P' OR last_known_voting_intention = 'A'";

if (!empty($criteria))
{
  $sql .= $criteria; // Append it to SQL query
}

mysql_query($sql);