We have a certificate table ties to the customer table containing the following fields:
Customer No. (key)
State (key)
Certificate No.
Effective Date (key)
Expiration Date
I'm trying to create rows which include any row where the expiration date is in a specified range and excludes any of those rows where a new certificate with an effective date on or after the beginning of the specific date range exists. In effect, we are looking for those customers where we need a new certificate since the existing one is almost expired and we have not yet received a new one. I can't seem to figure out how to exclude the certificate lines where we already have the new certificate. Any ideas?
