----- Original Message -----
From: <rob@xxxxxxxxx>
To: "Midrange Systems Technical Discussion" <midrange-l@xxxxxxxxxxxx>
Sent: Friday, March 26, 2004 3:21 PM
Subject: Re: Null in SQL select union


> I GOT IT!!!
>
> select ctype, color, count(*)
> from rob/titus
> group by ctype, color
> union
> select ctype,
>     case
>          when ' ' = ' ' then null
>          when ' ' <> ' ' then ' '
>     end,
>       count(*)
> from rob/titus
> group by ctype
> order by ctype, 2

Oh, I don't know exactly why this works, but it does. :-) Very nice but a
little complicated. And why is NULL for a result of a condition (following
"then") ok and as a constant in SELECT not. Or how do I have to specify it?

"SELECT NULL, color FROM cars" doesn't work and "SELECT *N, color FROM cars"
even not.

Titus

PS: Where could I learn a better english?




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