Re: SQL Intersect like problem

On Wed, 2003-02-05 at 16:39, Bruno Wolff III wrote:
> On Wed, Feb 05, 2003 at 10:17:09 -0500,
>   Dinesh Visweswaraiah <dinesh@trailblazingsolutions.com> wrote:
> > Bruno,
> >
> > I am sorry for being very clear.  The need is to identify an InvoiceId
> > from a *set* of ProductId and Quantity values.  A simple join will
> > not work because it is not one value of ProductId and one value of
> > Quantity.

Unless you are clearing these tables very frequently, it seems to me you
will very soon find duplicate combinations.  It is very likely (perhaps
not in your case?) that customers will repeat an order with the same
products and quantities as before, or that more than one customer will
send in the same order.

Why do you not add the invoiceid to the table with the products and
quantities?  This is the standard way to identify invoice lines with the
invoice.

--
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight, UK                             http://www.lfix.co.uk/oliver
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