Hi Kjell,

> > Firebird 2.1 supports MERGE for that purpose. And it too has a bug: if
> > multiple D records match the same M record, multiple updates take place
> > on that M record (in unpredictable order). But (afaict) without the
> > silly null-dependent mixing that you describe.
>
> Interesting. Is that supposed to be fixed and if so in what way?

I filed a ticket in January (http://tracker.firebirdsql.org/browse/CORE-2274)
which is currently still open.

The SQL standard says that - within the context of a MERGE statement - it
is a cardinality violation if multiple D (source) records match the same
M (target) record.
In that case, an exception should be raised.


Greetings,
Paul Vinkenoog