• Woiuld this work?

    UPDATE MirrorTable SET

      a = inserted.a

      b = inserted.b

      c = inserted.c

    FROM Inserted

    WHERE Inserted.id = MirrorTable.id

    INSERT INTO MirrorTable (id,a,b,c,d)

    SELECT id,a,b,c,d

    FROM Inserted

    LEFT JOIN MirrorTable ON MirrorTable.id = Inserted.id

    WHERE MirrorTable.id IS NULL

    Its late, im tired, so I didnt check if I did the sql right.  I'm sure its close though.