# Re: DECODE / CASE Question

From: <amerar_at_iwc.net>
Date: Mon, 2 Jun 2008 09:22:03 -0700 (PDT)

On Jun 2, 10:27 am, Vince <vinn..._at_yahoo.com> wrote:
> On May 30, 10:51 am, "ame..._at_iwc.net" <ame..._at_iwc.net> wrote:
>
>
>
> > Hi,
>
> > Say we have a very long DECODE statement like this:
>
> > DECODE(2,-99999,0,2) + DECODE(5,-99999,0,5) + DECODE(7,-99999,0,7) -
> > DECODE(8,-99999,0,8) * DECODE(9,-99999,0,9) stuff
>
> > Pardon the use of real numbers, that was for testing.
>
> > Now, I want to basically say if the value of this is 0, then 0 should
> > be returned, otherwise the result of the math should be returned.
>
> > Can I use a case statement for this somehow? Or do I enclose it
> > around another DECODE? Can I use the generated column alias???
>
> > Thanks!
>
> One possibility which doesnt get rid of the decodes, but leaves your
> formula simple:
> WITH x AS
> ( SELECT decode( a, -999999, 0, a ) AS a,
> decode( b, -999999, 0, b ) AS b
> ...
> FROM ...)
> )
> SELECT a + b + c - d * e
> FROM x

Almost perfect. Few weird things, unless I am messing it up:

create table test (
c1 varchar2(1),

```  c2   number,
c3   number,
c4   number,
```

c5 number);
```insert into test values ('A',2,4,6,8);
insert into test values ('B',1,3,5,7);
insert into test values ('C',2,-99999,6,8);
insert into test values ('D',2,-99999,6,-99999);
insert into test values ('E',-99999,-99999,-99999,-99999);

```

WITH x AS

``` (SELECT decode( c2, -999999, 0, c2 ) AS a,
decode( c3, -999999, 0, c3 ) AS b,
decode( c4, -999999, 0, c4 ) AS c,
decode( c5, -999999, 0, c5 ) AS d
```
FROM test)
SELECT a + b + c - d
FROM x;

A+B+C-D

```         4  - Perfect
2  - Perfect
-99999  - Should be 0 (2,-99999,6,8 = 2 + 0 + 6 - 8)
8  - Perfect
-199998  - Should be -99999
```
Received on Mon Jun 02 2008 - 11:22:03 CDT

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