Table join with scalar valued function

Question

I am trying to apply a join between a table and a scalar-valued function. I have been investigating and I think that it is not possible, but as I do not find any final conclusion saying that I want to be sure.

Do you know if it is possible?

I tried the following statement (do not work):

Select * 
from T1
join SVFunction on T1.id=SVFunction.id

And also this one (do not work):

Select * 
from T1
outer apply SVFunction (T1.id)

Thank you.

Answer 1

You have to try the following query

Select * ,SVFunction(id)
from T1

Scalar valued function return single value (not table) so you cannot use joins.

If it is a table valued function you can use the following as another way then Using Apply:

Select T1.* ,T2.*
From T1 INNER JOIN (SELECT * FROM SVFunction) AS T2 ON T1.id = T2.id 

And Maybe the problem is in the function code. so you can read more about Using Apply in this Technet topic