I am a self-taught php / mysql coder. Recently, I came across a dilemma where I needed to make a specific query. I had no idea how to do it, and none of the help texts seemed to address it. So I decided to treat it as a mathematical equation, and it worked. Now I am wondering if it is a stable query, or if perhaps it might be putting undue stress on the database and or dbuser, which the members use to access the database.

Here is the query. Would this have any adverse effects?

$result2 = mysql_query("SELECT * FROM ".$tableprefix."dbname_categories WHERE (catid = '$catid' OR optcatid = '$catid') AND parentcatid = '$parentcatid' ORDER BY displayorder ASC");

It is the (catid = '$catid' OR optcatid = '$catid') that I'm concerned about, of course.