Case 3 is what I was most interested in reading about since I faced a similar situation a while back. The solution is simply not a workable one in any cases that require the use of more then 2 variables. I racked by brain for a while before concluding that there was no other solution but to build dynamic SQL for my search problem. Fortunately, my database is accessed only by the web site and therefore I only had to grant SELECT right to the IUSR user.

The CASE in the ORDER BY is a neat trick that I didn't know about.

Good article, keep up the good work.