On 13/05/14 11:44, Oliver Kohll - Mailing Lists wrote:
The problem came when someone entered a record with no subject, but left it null. When this was copied over and present in both tables, the *next* time the join was done, a duplicate was created because the join didn't see them as matching (null != null).
Maybe you can use x IS NOT DISTINCT FROM y ? regards, Yeb
