I have a query that links three tables - A dosimeter imported table, A dosimeter allocation table and a personal info table. The dosimeter imported table is linked to the allocation table by dosimeter serial number. The allocation table is linked to the personal info by personal ID number. Dosimeters are issued to users for a period. They are then re-issued randomly to other users.
All of the readings for all of the monitoring periods are imported into the same table, so I can't check for duplicates at this stage. When the query runs I filter the readings for the period I'm looking for - 1st Quarter etc. The first time I run the query it works. If I import more data into the import table, without deleting the original data I get duplicates in the query.
Is there a way for the query to ignore EXACT duplicates when it runs?
Thank you.