Alias in long math expression

Question

Sorry the bad english. Im from Brazil.
Oracle 8.1.7.
This is just an example for a simple demonstration.
The following sql runs perfectly:
select
1,
2,
3,
(1+2+3) as soma,
4-(1+2+3),
(6-(1+2+3)) soma2,
15-(6-(1+2+3))
from dual
Notice that expression (1+2+3) repeats frequently.
i would like to reduce the sql size using alias (or something like that) for expression (1+2+3) in the same level of dual without using subqueries.
So, the sql above would stay:
select
1,
2,
3,
(1+2+3) as soma,
4-soma,
(6-soma) soma2,
15-soma2
from dual
This is perfectly comprehensible, but doesnt work. Oracle says invalid column name for alias soma2 or soma.
Is there a form to write the sql using alias or hints (and without using subqueries) ?
Thanks.

Answer 1

mlinhares,
I don't think your English is bad :)
I think you can do what you want by not having to type 1+2+3 every time.
If you are using SQL*Plus then you could use parameters
select
1,
2,
3,
(&&1) as soma,
4-(&&1),
(6-(&&1)) soma2,
15-(6-(&&1))
from dual
16:59:34 SQL> l
1 select
2 1,
3 2,
4 3,
5 (&&1) as soma,
6 4-(&&1),
7 (6-(&&1)) soma2,
8 15-(6-(&&1))
9* from dual
16:59:35 SQL> /
Enter value for 1: 1+2+3
1 2
SOMA 4-(1+2+3)
15-(6-(1+2+3))
1 2
6 -2
15
1 row selected.
Elapsed: 00:00:00.00
This way you enter the value only once.
If you want to change this to, say, 2+3+4,
just do the following:
SQL > undef 1
and run the query again. You will be prompted to enter the input again.
Shakti
http://www.impact-sol.com
Developers of Guggi Oracle - Tool for DBAs and Developers