Hi Dan,
I believe that the Sybase behavior is correct. I have logged bug 653 to
track this issue.
Regards,
-Rick
Dan Meany wrote:
I noticed that in Derby a unique constraint on two
columns A and B, with B nullable, will prevent
inserting two identical records that contain NULL in
B.
This is different from some other databases such as
Sybase that do allow it (I assume where the null
records are not in stored as part of the unique
index).
I noticed this while transfering data from Sybase to
Derby using Apache dbutils and getting rejected
duplicate records.