Re: isnull

Julie Hunt wrote:

> Sorry, I haven't come across ifnull

Ah, I think the documentation that came with 6.5.3 was wrong, because
http://www.postgresql.org/docs/postgres/functions.htm#AEN2257 has the function
nullif  where ifnull was in my documentation.  I don't get errors now, but it
just doesn't seem to do it's job.

playpen=> insert into tablea values (100, null);
INSERT 23168 1
playpen=> select * from tablea;
indexa|data
------+----    1|   1    2|   2    3|   2    4|   4    7|   7    6|   8    5|   8  100|
(8 rows)


playpen=> select *, data from tablea;
indexa|data|data
------+----+----    1|   1|   1    2|   2|   2    3|   2|   2    4|   4|   4    7|   7|   7    6|   8|   8    5|   8|
8 100|    |
 
(8 rows)

playpen=> select *, nullif(data, 9) from tablea;
indexa|data|case
------+----+----    1|   1|   1    2|   2|   2    3|   2|   2    4|   4|   4    7|   7|   7    6|   8|   8    5|   8|
8 100|    |
 
(8 rows)



>
> Julie
>
> >Oops, my mistake.  I meant ifnull.  Whenever I try to use ifnull I get an
> >error so I have to use a case when a = null then default else a end.
> >
> >Julie Hunt wrote:
> >
> >> There is a space between is and null: is null
> >>
> >> Regards
> >>
> >> Joseph Shraibman wrote:
> >>
> >> > Could someone give me an example of isnull?  Whenever I try it I get an
> >> > error message.
> >