Dubletter i én tabel

it sounds as though you should normalise your database.

a table with person information, another table with different categories and then a link table which contains relationships between the two table and also a field containing yes/no

Yeah I know, it isnt my db, im just helping out, I want to have it cleaned up before changing the layout.

ther is no quick and easy way to "clean up" so I suggest that changing the layout at the same time will save work.

Okay, and do you have any suggestions on doing that, so I dont have to do it manually?

You will need to make the new tables and then make some queries which copies the data from the old table into the new. There is obvioulsy some manual work in designing the new tables and making the queries, but you wont need to cut and paste data between tables.

If you can make the new tables I can assist with making the new queries once I know the layoutof your tables.

Du kan dele det op i en forespørgsel pr. kategori...

Dvs. du laver 13 forespørgsler a'la:
SELECT PersonTabel.email, PersonTabel.kategori01
FROM PersonTabel
GROUP BY PersonTabel.email, PersonTabel.kategori01
HAVING (((PersonTabel.kategori01)=True));
osv.. en for hver kategori

Så laver du en som finder den første (eller sidste) person for hver email, a'la:
SELECT First(PersonTabel.Person) AS FirstOfPerson, PersonTabel.email
FROM PersonTabel
GROUP BY PersonTabel.email;

og så sætter du dem sammen, bare husk at du skal ikke have group by og du skal lave alle joints så de viser alle personer, men kun de kategorier, som har samme email. I mit forsøg, som havde 3 kategorier, kom det til at se sådan ud:
SELECT KatFirstPerson.FirstOfPerson AS Person, KatFirstPerson.email, Kat01.kategori01, Kat02.kategori02, Kat03.kategori03
FROM ((KatFirstPerson LEFT JOIN Kat01 ON KatFirstPerson.email = Kat01.email) LEFT JOIN Kat02 ON KatFirstPerson.email = Kat02.email) LEFT JOIN Kat03 ON KatFirstPerson.email = Kat03.email;

Du laver så en kopi af din tabel, sletter alle data og kopier disse data over i den. Så skulle du have det ønskede resultat!~)