The below code works fine in SQL server to identify customers with duplicate order numbers, however, I want to use it in access, but realised count(distinct) is not available there. Can someone help amend?
SELECT o.*
FROM (SELECT OrdNum, COUNT(DISTINCT CustId)
FROM OUTPUT
GROUP BY OrdNum
HAVING COUNT(DISTINCT CustId) > 1
) as oc INNER JOIN
OUTPUT as o
on oc.OrdNum =
rdNum
SELECT o.*
FROM (SELECT OrdNum, COUNT(DISTINCT CustId)
FROM OUTPUT
GROUP BY OrdNum
HAVING COUNT(DISTINCT CustId) > 1
) as oc INNER JOIN
OUTPUT as o
on oc.OrdNum =
rdNum
