Conditional Select Statement

Hello dbForumers,

Yet another puzzling question. I remember I saw somewhere a particular syntax to select a column based on a conditional predicate w/o using a user defined function. What I want to accomplish is this : SELECT (if column colA is empty then colB else colA) as colC from SomeTable. Possible ? Not possible? Have I hallucinated ?

Thank You!possible.
select (case colA when ='' then colB else colA end) as colC

Originally posted by Rollmops
Hello dbForumers,

Yet another puzzling question. I remember I saw somewhere a particular syntax to select a column based on a conditional predicate w/o using a user defined function. What I want to accomplish is this : SELECT (if column colA is empty then colB else colA) as colC from SomeTable. Possible ? Not possible? Have I hallucinated ?

Thank You!|||Yay, right on target.

But now I have some difficulties testing the NULL state... the syntax: ...(CASE VTE1 WHEN NULL THEN ACHN ELSE VTE1 END) AS COND_ACHN... won't throw any errors but wont work as excepted since it always sends the ELSE case no matter what...|||select isnull(vte1,achn) as COND_ACHN
or

select (CASE WHEN VTE1 is NULL THEN ACHN ELSE VTE1 END) AS COND_ACHN

Originally posted by Rollmops
Yay, right on target.

But now I have some difficulties testing the NULL state... the syntax: ...(CASE VTE1 WHEN NULL THEN ACHN ELSE VTE1 END) AS COND_ACHN... won't throw any errors but wont work as excepted since it always sends the ELSE case no matter what...|||Yay, right on target.

But now I have some difficulties testing the NULL state... the syntax: ...(CASE VTE1 WHEN NULL THEN ACHN ELSE VTE1 END) AS COND_ACHN... won't throw any errors but wont work as excepted since it always sends the ELSE case no matter what...|||To determine if an expression is NULL, use IS NULL or IS NOT NULL rather than comparison operators (such as = or !=).
follow the code of my previous message.It should work for u.

Originally posted by Rollmops
Yay, right on target.

But now I have some difficulties testing the NULL state... the syntax: ...(CASE VTE1 WHEN NULL THEN ACHN ELSE VTE1 END) AS COND_ACHN... won't throw any errors but wont work as excepted since it always sends the ELSE case no matter what...|||I just had to remove the 'VTE1' in ...(CASE VTE1... for the predicate to work accordingly =) anyways thanks a lot it works just fine now =)