Join question

[Williams, Travis L, NEO]

Question,

I have a table (1) with 2 col (a & b) where b can sometimes be null. I need a query that if B is null I get back the contents of A.. but if B is not null I do a join on it and table (2) col c to get the contents of table (2) col d.. I can do this in multiple queries.. but was wondering if I could do it in 1.

Travis

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[Thomas A. Lowery]

Does using a union count as one query?

select a from tst_1 where b is null
union
select d from tst_2 t2 join tst_1 t1 on (t1.b = t2.c)
where t1.b is NOT null
On Thu, Aug 28, 2003 at 05:55:27PM -0400, Williams, Travis L, NEO wrote:

Question,

I have a table (1) with 2 col (a & b) where b can sometimes be null. I
need a query that if B is null I get back the contents of A.. but if B
is not null I do a join on it and table (2) col c to get the contents
of table (2) col d.. I can do this in multiple queries.. but was
wondering if I could do it in 1.

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