• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 262
  • Last Modified:

Trigger Update not working if starts null

If got a simple trigger which is to update a log table (which I unfortunately need), however if the value of `phoneNumber` is its default of Null, when I update it like:-
UPDATE `contract` SET `phoneNumber` = '44464' WHERE `contract`.`priID` = 8;

Open in new window

I dont get a line in the logger, however if I execute again differently so the so OLD.`phoneNumber` isnt null then trigger fires fine and runs the insert command.

My trigger code is:-
Begin
IF OLD.`phoneNumber` <> NEW.`phoneNumber` THEN
             INSERT INTO `mobilephones`.`_logger` (`dateTime`, `connectionID`, `table`, `priID`, `feild`, `newValue`,`action`) VALUES (NOW(), CONNECTION_ID(), 'contract', NEW.`priID`, 'phoneNumber', NEW.`phoneNumber`, 'Update');
END IF; 
End

Open in new window


Any ideas what Im doing wrong?
0
tonelm54
Asked:
tonelm54
1 Solution
 
Julian HansenCommented:
The article below might shed some light

http://coldfusionbeyond.com/post.cfm/mysql-trigger-flakiness-and-null-in-comparisons

Basically saying that comparing null to null gives null and not 1 (equal).

Not sure if the suggested work around can help but it might give some insight.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now