Selecting not null column

Question

I have a table with varbinary(max) column and nvarchar(max) column. One of them is null and the other has a value.

I would like to return the column that has the value as a varbinary(max) column. So far I have tried this, that does not work:

SELECT 
      A =  
      CASE A
         WHEN NULL THEN B
         ELSE A 
      END
FROM Table

Answer 1

SELECT COALESCE(A, CAST(B As varbinary(max)))

UPDATE: In response to comments (thanks) and assuming B is the nvarchar(max) column, I have moved the CAST inside the COALESCE