Question

Take these two example tables:

Table A
Name   FirstOrLast
Jeremy First
Smith  Last
Mark   First
David  First


Table B
Name
Jeremy
Smith
Mark
David
Jones
Jack

I would like the output to be this: Output only first names, but if Table A doesn’t record if it’s a first or last name, output it anyway. The correct output would be:

Jeremy
Mark
David
Jones
Jack

I’ve tried accomplishing this with an outer join, like so:

select
  B.Name
from
  A, B
where
  A.name = B.name(+) and
  A.FirstOrLast = 'First';

but no luck. How can I do this?

Answer 1

When you perform a left outer join and there is no record in A, a.firstOrLast will be null. While you’re at it, you might as well switch to the standard syntax for joins:

select
    B.Name
from
    B
left outer join A on A.name = B.name
where
A.firstOrLast is null or A.firstOrLast = 'First';

However, the old syntax should also work:

select
    B.Name
from
    A, B
where
    A.name = B.name(+) and
    (A.firstOrLast is null or A.firstOrLast = 'First');