[GRASS-user] better way to add layer categories?

[Shane Litherland]

Hi all,

I have a vector, with three layers each connected to a different table.

I heard about v.db.join and thought that would be a great tool, which it
is but it doesn't satisfy me for this purpose, as it seems to result in
the joined info displaying like one big table with all data from joined
tables together.

I would prefer to keep the info from each table on separate layers just
so I can do things a particular way.

Currently when I digitise an area, I add the cat for each layer.
Is there a better way to do it, a bit like an update query? Because I
could digitise the areas and do the cats for the first layer, then the
other layers share a common value in a 'date' field which could join
them. or a partly-automated, partly-manual approach where I tell GRASS
to add to vector layer 2, a cat value of x, when the date (of layer one)
=y

I have spent some time going through GRASS manual for various things,
but so far haven't had anything hit me in the face as being an answer to
this... maybe I need glasses... ;-)