Question

Using SQL Server 2008.

Here is a simplified example of my problem:

WITH    cte ( a )
          AS ( SELECT   1
               UNION ALL
               SELECT   NULL
             )
SELECT * INTO a_tmp FROM cte

SELECT * FROM a_tmp

This creates the table called a_tmp with a nullable int column.

The next snippet, however creates the table with a non-nullable column:

WITH    cte ( a )
        AS ( SELECT   1
        UNION ALL
        SELECT   2
            )
SELECT * INTO a_tmp FROM cte

How can I change the second snippet to force the table to be created with all its columns nullable?

Answer 1

Make it into a computed expression as generally these get treated as NULL-able unless wrapped in ISNULL()

WITH    cte ( a )
        AS ( SELECT   CAST(1 AS INT)
        UNION ALL
        SELECT   2
            )
SELECT * INTO a_tmp FROM cte