select InvoiceDate, InvoiceAmount
from invoices
group by InvoiceDate, InvoiceAmount
having count(*) > 1
if you want the whole invoice
select *
from invoice i1
join
(select InvoiceDate, InvoiceAmount
from invoices
group by InvoiceDate, InvoiceAmount
having count(*) > 1
) i2
on i1.InvoiceDate = i2.InvoiceDate
and i1.InvoiceAmount = i2.InvoiceAmount
order by InvoiceDate, InvoiceAmount
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Cursors are useful if you don't know sql.
DTS can be used in a similar way.
Beer is not cold and it isn't fizzy.