importing data into different tables AND check for duplicates

[FrontV]

Hi,
I am trying to import data from excel into a database, while at the same time preventing duplicate records. Our database will contain many thousands of persons and their contact info and we will add regularly, so something that can be automated would be the best. I am making a form with some buttons which will do the different steps.

The excel data consists of names, and email addresses and some more info, but the main thing to identify people will be name and email. Each person might also have more email addresses so I made a subtable in the DB which will only have email addresses linked to each unique personID in the main table of persons.

Importing:


I think I should import all data into a temporary table in Access and from there have it split into different tables with append queries. Correct me if i'm already wrong here, please. Anything more simple or easy is always welcome.

Checking for duplicates:
But, I want to make sure we do not add persons into the database of which we already have a record. How do I prevent this, as people can of course have similar names, but still have different email addresses. What would be the best place to check, before table is split and sent to the different tables, or after? And if I do it after, how do I find out if someone with the same initials actually has different email address and other properties, such as address and is then a different person?

I have been stuck on this one for more than a week now...

[RayMilhon]

I have done something similar. Your import routine is the correct way to go (in my humble opinion) What you need to do is in your update queries include the table you're putting the data into make it a left outer join on all of the fields that determine if it's a duplicate or not and set the criteria on those fields to = Null.

[FrontV]

Good to hear I appear on the right track. I'll give the outer join a go and see if it works. Thanks!