Dataview, datagridviews and access tables.... would this work?

Dear reader

I am wondering if this would work.... lets say this example

I have 2 tables in a access-database which are related by ZIP-code and HouseNumber

where the relation ZIP-code and HouseNumber is a key and an unique relation in my database

table one

ZIP-code HouseNumber Streetname

table two

ZIP-code HouseNumber Xinfo Yinfo

Using some SQL and a datatable dataview i populate a datagridview with columns like 

ZIP-code HouseNumber Xinfo Yinfo Streetname

I want to change data in the datagridview and being able to store it back in the database-tables.

Would this work since the relation is unique.... and does storing back allow to override the data currently in teh database?

I hope you understand my question.... thx anyway