RE: [HACKERS] Associative Operators? (Was: Re: [NOVICE] Out of f rying pan, into fire)

I have not been able to track down any information on coalesce nor get
PostgreSQL execute it. Where is this documented?

-----Original Message-----
From: Zeugswetter Andreas IZ5
[SMTP:Andreas(dot)Zeugswetter(at)telecom(dot)at]
Sent: Wednesday, March 17, 1999 1:29 AM
To: hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] Associative Operators? (Was: Re:
[NOVICE] Out of f rying pan, into fire)

>
> >> I tried to create a C function to overcome this but noticed
that if any
> >> parameter in my C function is NULL then the C function always
returns
> NULL.
> >> I saw some references in the archives about this issue but was
unable
> to
> >> determine where it was left. What is the status of this issue?
>
Yes, this is current behavior.

> Would a compromise be to add DECODE and NVL ?

The Standard has the more flexible function COALESCE, which is
already
implemented in postgresql.
Simply say
coalesce(field_that_can_be_null,value_to_return_insteadof_null)

Andreas