matching records from 2 different data sources
I am setting up a database to track patients admitted to the hospital with pneumonia. There are 2 different data sources that I need to match up to find patients who are missing a specific piece of data.
Datasource #1 is a listing of the admitted pneumonia patients and contains patient name, ID#, and [bloodtest] date/time.
Datasource #2 is a list of all patients who had [bloodtest] perfomed and contains name, ID# and [bloodtest] date/time.
I need to find patients who exist in datasource #1 and have no entry for [bloodtest] date/time but who have that information listed in datasource #2.
I have separate tables set up for each datasource and but am not sure if there's a way to set up a relationship that will display what I'm looking for.