Data pulling through 3 tables

[hugo35]

Hi, I'm new to access 2007 and having problems with creating relationships between multiple tables. Here are the tables in a simplified form:

MITMAS - 400 items
Item No. (primary key)
Name

MITLOC - 300 items
UNID (primary)
Item No.
Location

MITPOP - 200 items
UNID (primary)
Item No.
Alias No.

The MITMAS table holds all the basic data for all the items I have and the Item No. is not duplicatable in the table. The Item No.s are duplicatable in the other 2 tables. The aim is to get a table with all the Item No.s from the MITMAS table and have their matching Alias No.s and Locations. Then, for example, when I allocate a Location to a MITMAS Item No. that didn't previously have one it would create a new part in the MITLOC table and pull the Item No. from the MITMAS table.

So far I have created a relationship (one-to-many) from the MITMAS Item No. to each of the Item No.s in the other two tables with a join type including all entries from MITMAS. I have Queryed the relationship and this gives a table with all the Item No.s from MITMAS and the Alias No.s and Locations where there is a match. I have set the RecordsetType to Dynaset (Inconsistant Updates) to open the fields to editing.

However when I put in a Location into a field that didn't previously have one it comes up in the MITLOC table as a new item but hasn't pulled the Item No. data from MITMAS. How can I create this relationship?

Clear as mud?

Thanks
Hugo