Finding Duplicate Values

1

Hi,

I'm just starting my SQL journey, it's all very foreign so be kind.

In our accounting system there is an events module that triggers particular rules. I'm attempting to create a trigger where when a purchase order is entered with the same @custorderno (po number) it triggers the alert.

any help would be very much appreciated.

SELECT @CUSTORDERNO
GROUP BY @CUSTORDERNO
HAVING COUNT (*) > 1

2

The following assumes that you have a table named YourCustomerOrdersTable and that there is a column in that table named CustOrderNo which has all the already existing CustOrderNo.

IF EXISTS
(
    SELECT
        *
    FROM
        YourCustomerOrdersTable
    WHERE
        CustOrderNo = @CustOrderNo
)
BEGIN
    -- do what you need to do here.
END