How can place NULL value in View definition?

I want to UNION two table with the following SQL statement:

create or replace view testing as
select a.*, b.do DO from test1 a, test2 b where ... UNION
select a.*, NULL DO from test1 a, test2 b where ...

b.DO is integer type, however, I got the error message as the datatype mismatch in NULL column (NULL column is UNION with b.do column, I think integer type cannot match with NULL).

Is it possible to place the NULL value (i.e. don't place anything) in the corresponding column in view definition?

Thanks,
David

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Before you buy. Received on Thu Dec 16 1999 - 11:05:43 CST