>>> In particular, columns are populated with values if they are not specified
>>> in the update statement which is used.
>>> Usually with an expression like this:
>>>
>>> IF NOT UPDATING('IS_CANCELED')
>>> THEN
>>> :new.is_canceled := ...;
>>> END IF;
>>>
>>> I have not found anything similar in PostgreSQL. What is the common
>>> approach to this problem?
>>
>> PostgreSQL doesn't have an exact equivalent. Typically, the OLD and NEW
>> values are compared and then action is taken based on that. For example, in
>> PL/pgSQL:
>>
>> IF NEW.is_canceled IS NOT DISTINCT FROM OLD.is_canceled THEN
>> NEW.is_canceled := etc etc ;
>> ENDIF;
>
> Unfortunately, this doesn't quite fit the logic I need. I don't need to know
> if the value was changed, but if the application that sent the UPDATE
> statement knows the column or not.
> In our case, a number of different applications access the database, which
> may or may not know the column depending on the version.
> And it is also regularly the case that SQL statements are executed directly
> in an SQL client by hand. And in the event that the column was not specified
> in these statements, a trigger is supposed to fill the value.
>
>> There's currently no way to detect if the column was simply not mentioned at
>> all in the UPDATE statement.
>
> Hmm, that's odd.
See thread below:
https://www.postgresql.org/message-id/VisenaEmail.26.7cbf2947c8d23ceb.1769a2755ff%40tc7-visena
I found that thread already, but It doesn't not provide a solution to my
problem.
--
Dirk Mika
Software Developer
mika:timing GmbH
Strundepark - Kürtener Str. 11b
51465 Bergisch Gladbach
Germany
fon +49 2202 2401-1197
[email protected]
www.mikatiming.de
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