Subject expression evaluation
Author Lauri Zoova
Hi!

If i have an after(or before, does not matter) update trigger with the
following in it:
if new.field <> old.field then [do something that takes a long time and
needs to be done only when this field changes]

..it evaluates to false when old value is null.

This would solve it:
if ((new.field <> old.field) or ((new.field is not null) and (old.field
is null))) then ...

..but it's very inconvenient when i have more than one field in the
condition. I solved my problem (a while ago) in the client programm (had
4 fields). So this is not an active problem, but i'm just being curious.

This seems absurd. Is this a feature or a bug or does some standard say
that this is the way it should be?
Again - is there another way to do this?

(tested with fb1 & 1.5)


BR,
Lauri
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