Thank Somni for the "clue." In my production code I was trying to insert hex values for web colors, e.g., c023ab, which was producing the "unknown column" error. When I substituted simple strings, e.g., "aaaaaaaa" for those values, I was fine. So, it must be the bug of which you and this node spoke of. My web host is running MySQL 3.23.58, but can't find a convenient listing of all the fixes since then (like you can with CPAN modules). So, I can't say positively that is the problem.

And interestingly, I can't replicate the error in a stripped-down version, I can only get it in my larger program. Anyway, for now, I must forego the monkish ways of placeholders and place my quoted values directly into my INSERT statement, which, of course, fixes the immediate problem.

If I find out more, I will update this node.