If exists from within a select statement.

I have a simple SQL statement, I need to populate columns from several
tables.
I need to populate some of the columns depending if there is data in a
child table that matched the parent table (a one to many relationship).
How can I put in an "if exists" into a select statement?
I need results that will be
file_a.first, file_a.second, file_b.first (when file_a.third = "y"),
file_b.first (when file_a.fourth = "y") ..
so kinda like :
select file_a.first, file_a.second,
if file_a.third = "y" then select file_b.first from file_b ..
if file_a.fourth= "y" then select file_b.first from file_b ..You can=B4t use specify dynnamic resultssets until you use dynmaic SQL
to display the columns.
http://www.sommarskog.se/dynamic_sql.html
Without dynamic SQL you could display the columns but fill them in
conditionally:
SELECT
OneTable.SomeColumn0
CASE OneTable.SomeColumn0 WHEN 'Y' THEN OtherTable.SomeColumn0 END...
But assuming that fileA is your parent table which attributes from
which row do you want to display ? If there are two rows returned for
one parent row, your query like the above one wouldn=B4t be reliable.
Perhaps it would be better to post your DDL and sample data that our
thoughts would=B4nt bw based on assumptions:
http://www.aspfaq.com/5006
HTH, jens Suessmeyer.sql