Please see attached spreadsheet.
I have two columns of data and need to creat a query to find missing records.
Document_ID and Host_Reference
Where Host_Reference IS NOT NULL, the corresponding Document_ID is denoted as an Attachment and the record listed in Host_reference is denoted as the HOST.
Where Host_Reference IS NULL, Document_ID is denoted as a Single.
I am having the problem in this dataset of identifying ALL Attachments in Document_ID that refer to HOSTS that don't exist.
ie: There is a host_reference entry, however it does not exist in Document_ID
From the above example - ABC.002.005.0116 is an attachment to ABC.002.005.0112 - however ABC.002.005.0112 does not exist.