PHP and MySQL optional WHERE conditions

Question

I have the following problem: I want to let a user apply filters to a DB search. I have three filters, A, B and C. All of them can be \"empty\", as in, the user doesn\'t care a

Answer 1

Try this:

$db_q = "Select * from table ";

if ($A != "any" || $B != "any" || $C != "any")
{
    $db_q .= "where ";
}

$firstCondition = true;

if ($A != "any")
{
   if (!$firstCondition)
       $db_q .= "and ";

   $db_q .= "row1 = '$A' ";
   $firstCondition = false;
}

if ($B != "any")
{
   if (!$firstCondition)
       $db_q .= "and ";

   $db_q .= "row2 = '$B' ";
   $firstCondition = false;
}

if ($C != "any")
{
   if (!$firstCondition)
       $db_q .= "and ";

   $db_q .= "row3 = '$C' ";
   $firstCondition = false;
}