On Tue, 2005-08-16 at 17:31 +0300, Andrus wrote:
> Each invoice must have at leat one row.
>
> I want that transaction commit fails if invoice header is inserted
> without
> any row in invoice rows table.
>
> How to prevent inserting invoice headers without rows ?
You could have a NOT NULL foreign key in the header table referencing
the detail table. You then have declarative integrity guaranteeing that
at least one detail entry exists for each header entry.
How your system populates this column is another question. In this case
maybe some client-side logic would be cleaner than a trigger-based
solution.
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
