Select from 1 table only if a value does not exist

Question

Hello all,
I'm having problems devising a single select statement to accomplish a single return value. I have tried variations of DECODE and COALESCE, but it's escaping me.
I have two tables that are as follows:
NAME
ID, FULLNAME
1, Senior
2, Junior
3, Mister
4, Senor
5, Miss
ABBREVIATION
ID, ABBREV
1, Sr
2, Jr
3, Mr
5, Ms
What I would like to do is select from the NAME table only if the value does not exist in the ABBREVIATION table.
Ideally if I were to do something such as:
SELECT * FROM .... WHERE (ID=1 or ID=2 or ID=4) ....
I would receive the following output:
1, Sr
2, Jr
4, Senor
Thanks for reading!

Answer 1

You want an outer join.
SELECT decode(a.abbrev, NULL, n.fullname, a.abbrev)
FROM name n,
abbreviation a
WHERE n.ID = a.ID(+)
  AND ....Something like that.
Full example:
with n as (
select 1 as ID, 'Senior' as FULLNAME from dual UNION ALL
select 2 as ID, 'Junior' as FULLNAME from dual UNION ALL
select 3 as ID, 'Mister' as FULLNAME from dual UNION ALL
select 4 as ID, 'Senor' as FULLNAME from dual UNION ALL
select 5 as ID, 'Miss' as FULLNAME from dual),
a as (
select 1 as ID, 'Sr' as ABBREV from dual UNION ALL
select 2 as ID, 'Jr' as ABBREV from dual UNION ALL
select 3 as ID, 'Mr' as ABBREV from dual UNION ALL
select 5 as ID, 'Ms' as ABBREV from dual)
select decode(a.abbrev, NULL, n.fullname, a.abbrev)
from a, n
where n.id = a.id(+)
order by n.id;
ID                     DECODE(A.ABBREV,NULL,N.FULLNAME,A.ABBREV)
1                      Sr                                       
2                      Jr                                       
3                      Mr                                       
4                      Senor                                    
5                      Ms                                       
5 rows selectedEdited by: tk-7381344 on Nov 17, 2008 1:31 PM