I have what seems a very simple issue but has been a major problem for
me to resolve...

I have 2 tables; 1 (widgets) describes my items in detail and includes
a unique primary identifier for each type of widget (not an
autonumber).  The second (location) describes where the widgets are
stored.  The 2 tables are linked by the primary identifier.  The
locations table includes the storage room, row, shelf and box.  My
database is set up so that new widgets are entered via a form (and
subform for location) and if they are moved from one location to
another, a new row is made with the new location in the location table.
Since this row has the date, a totals query with max date and the
primary ID joined to a current location query will tell me the current
location.

This part has been easy.  The hard part comes when I move a box of
widgets.  Each box contains many different widgets, though with some
similar aspect, and has a unique id.  I have set up my new location
form so that I can enter the primary ID, the Box ID or both.  The
trouble is that if I move an entire box, the primary ID field for the
new location is empty, and, as a result, when the query is run I don't
get what I want.  The responses I get are myriad and depend on the
joins but so far none have been quite right.

Any suggestions would be greatly appreciated.  I'm a advanced
beginner/intermediate with access.