I have a table1 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 "select d from table2 where d like '%b%'" There is nothing to join between table1 & table2 (unless you can join on likes
You can do something like this, but I can't promise any great performance:
select case when b is null
then a
else (select d from table2 where d ~* b) end as value
from table1;
jmelloy=# select * from table1; a | b ---+------ 1 | 2 | 3 | 4 | for 5 | asdf 6 | coo (6 rows)
jmelloy=# select * from table2;
d
----------
forsythe
manasdf
cool
(3 rows)jmelloy=# select case when b is null then a::varchar else jmelloy-# (select d from table2 where d ~* b) end as value jmelloy-# from table1; value ---------- 1 2 3 forsythe manasdf cool (6 rows)
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