Dynamic SQL in Triggers

[Frederic Steinfels]

I wanted to use dynamic sql in triggers. I had to figure out that this feature is disabled/broken/prohibited/not implemented. Other DB systems are said to support this. Are there any plans to fix this?

The problem at hand: I want to have a dynamic list of tablenames and rownames that I want to log. Something like this:

SET @s = CONCAT("SELECT 1 INTO res WHERE NEW.`",this,"`<=>OLD.`",this,"`");
PREPARE stmt FROM @s;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

IF (res=1) THEN
INSERT INTO `adminmessages` SET `message`=CONCAT(this," has changed");
END IF;

For now, I will have to hardcode all rows I want to log. Very ugly.