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mysqltriggersnul

Comparison in mysql Trigger for Null Value

This is my trigger after update record. The old.ActivatedDate always is Null and new.ActivatedDate always is not Null.

This is my code, but it is not working because its condition is not returning true to continue other jobs.

SET @OldActivateDate := OLD.ActivateDate;
SET @NewActivateDate := NEW.ActivateDate;

IF(@NewActivateDate IS NOT NULL AND @OldActivateDate IS NULL AND @OldActivateDate!=@NewActivateDate)
THEN
/* Do Some Functionality */
END IF;

I tested this method also, but again it is not working.

if (@NewActivateDate != @OldActivateDate) and ( @NewActivateDate is not null and @OldActivateDate is null )
THEN
/* Do Some Functionality */
END IF;
Solution

  • If you want to check that old.ActiveDate should be NULL and new.ActivateDate should not be NULL, then why do you have other conditions. Just use:

    IF (@NewActivateDate IS NOT NULL AND @OldActivateDate IS NULL) THEN
    . . .
END IF