SQL Error: ORA-01791: not a SELECTed expression 01791. 00000 - "not a SELE

Question

guys getting an error with a simple query. help me out please.
the query is:
select DISTINCT(product_code ||' ' || subproduct_code ||' '|| position_number) from alm_owner.wrr_recon_source order by product_code, subproduct_code, position_number;
Error report:
SQL Error: ORA-01791: not a SELECTed expression
01791. 00000 - "not a SELECTed expression"
*Cause:   
*Action:
any help is much appriciated.

Answer 1

Raghunadh wrote:
Yes. If he wants the result to be sorted on product_code, he can do something like:
select DISTINCT Det from (
select product_code ||' ' || subproduct_code ||' '|| position_number as Det
from alm_owner.wrr_recon_source)
order by substr(product_code,1);This will atleast sort the first section of the result. For example,
@raghu> select distinct det from (select empno ||' ' || ename ||' '|| sal Det from emp);
DET
7499 ALLEN 1600
7369 SMITH 5600
7844 TURNER 7000
7900 JAMES 950
7654 MARTIN 6500
7698 BLAKE 2850
7788 SCOTT 3000
7934 MILLER 6600
7566 JONES 2975
7839 KING 5000
7521 WARD 1250
7369 SMITH 800
7844 TURNER 1500
7876 ADAMS 1100
7934 MILLER 1300
7876 ADAMS 6200
7782 CLARK 2450
7521 WARD 6500
7900 JAMES 5900
7902 FORD 3000
@raghu> select distinct det from (
2  select empno ||' ' || ename ||' '|| sal Det from emp) order by substr(det,1);
DET
7369 SMITH 5600
7369 SMITH 800
7499 ALLEN 1600
7521 WARD 1250
7521 WARD 6500
7566 JONES 2975
7654 MARTIN 6500
7698 BLAKE 2850
7782 CLARK 2450
7788 SCOTT 3000
7839 KING 5000
7844 TURNER 1500
7844 TURNER 7000
7876 ADAMS 1100
7876 ADAMS 6200
7900 JAMES 5900
7900 JAMES 950
7902 FORD 3000
7934 MILLER 1300
7934 MILLER 6600(Dont worry about the records in emp table, I inserted some sample duplicate records to test something)I don't understand what SUBSTR(det,1) is for. That's the same as ORDER BY det surely? Which is also the same as ORDER BY empno ||' ' || ename ||' '|| sal....
Edited by: Bravid on Mar 2, 2012 11:56 AM