An update to what I had said earlier
Code:
INSERT INTO user (UserID, UserKey, UserDisplayName, UserEmail) values("00000000-0000-0000-0000-000000000000","00000000-0000-0000-0000-000000000000","MyDummyUser@dummy.com","MyDummyUser@dummy.com")
(I don't think __deviceid is needed so lowered it to 4 values)
Just remember that the UserID has to be unique within the User table.
This approach SHOULD be independent of database version.