create a trigger that checks intries in a table

[fabiez]

I'm trying to create a trigger that checks intries in a table.

 CREATE TRIGGER check_stored_stars BEFORE INSERT ON stored_stars
 FOR EACH ROW
 BEGIN
   IF NEW.user_id = OLD.user_id AND NEW.star_id = OLD.star_id
   ELSE
     INSERT INTO stored_stars(user_id, star_id)
	 VALUES(NEW.user_id, NEW.star_id);
   END IF;
 END;

But I get an error saying: #1363 - There is no OLD row in on INSERT trigger

How do I solve this?

[ginerjm]

Looks/sounds like an sql question, not something on a php forum.

[kicken]

If you're trying to prevent duplicates on the user_id,star_id combo then just set a UNIQUE constraint on those columns.

CREATE UNIQUE INDEX IX_UserStar ON stored_stars (user_id, star_id)

The reason for the error is exactly as it says, when you are doing an INSERT query, there is only NEW data, not any OLD data.

[fabiez]

thanks