[GRASS5] Layers Clarification

[twiens]

----- Original Message Follows -----
From: Michael Barton <michael.barton at asu.edu>
To: Moritz Lennert <mlennert at club.worldonline.be>
Cc: Trevor Wiens <twiens at interbaun.com>, GRASS5
<grass5 at grass.itc.it>, Radim Blazek
<radim.blazek at gmail.com>, Helena Mitasova
<hmitaso at unity.ncsu.edu>, Martin Landa
<landa.martin at gmail.com>
Subject: Re: [GRASS5] Layers Clarification
Date: Tue, 07 Mar 2006 10:43:28 -0700

> >> I want to embellish on Radim's response a bit.
> >> 
> >> ONE vector object can join with can be joined with ONE
> attribute table for >> EACH "layer" it has. If it has ONE
> layer, it can join with ONE table, if it >> has TWO layers
> , it can join with TWO tables. >> 

Michael,

In Radim's example of v.clean

    1
+-----------+
              2
        +----------------+

v.clean yielding

  1      1,2   2
+------+----+------------+       

According to Radim's text the result is still in one layer. 

Thus I must conclude that although GIS objects can only
connect to one table per layer, GIS objects can connect to
more than one row in the linking table thus supporting many
to one joins as well as one to one or one to many.

This seems odd. What am I missing here.

T