[GRASS5] db.columns and v.info -c

[Maciek Sieczka]

On wto, 2005-11-22 at 15:23 +0100, Markus Neteler wrote:
> On Tue, Nov 22, 2005 at 02:53:43PM +0100, Maciek Sieczka wrote:
> > On wto, 2005-11-22 at 10:31 +0100, Radim Blazek wrote:
> > > On 11/22/05, Maciek Sieczka <werchowyna at epf.pl> wrote:
> > > > Hi
> > > >
> > > > I'm wondering if functionality of db.columns and v.info -c shouldn't be
> > > > merged into one command. Maybe extend db.columns to report types (other
> > > > info? say: number of records per column, check if null records
> > > > present/absent, number of null records?) and remove "-c" from v.info?
> > > >
> > > > Maciek
> > > 
> > > How do you want to merge v. and db. commands?
> > 
> > Isn't v.info -c an example?
> 
> No: it shows the columns of a table *connected* to a
> vector map.

I know.

> But you can have many tables not connected to vector maps
> in your database. The v.* commands do not see them, but
> the db.* commands do see them.
>  
> > > One works on vector and the other on table.
> > v.info -c works on a table
> 
> Yes, but only on a table connected to a certain
> vector map.



I'm affraid I wasn't explicit enough in my fisrt post. Other words then.

Is it necessary to maintain "v.info -c" when db.columns, in conjnction
with "v.db.connect -p", provides the same functionality?

In order to know what table my_vector is connected to I do "v.db.connect
-p my_vector", then db.columns on the resulting table name to learn
about it's columns (using v.db.connect for learning the name of
connected table is pretty intuitive, as it is used also for connecting
and distonecing tables, should be no problems here for newbies).

Currently both "v.info -c" and db.columns print the column name -
doubled functionality. Only v.info -c prints the column type tough.
Instead of maintaing both commands, wouldn't it be better to implement
printing the column type in db.columns (or make it print even more
information besides coulmn name and type) and get rid of "-c" in v.info?

I'm rising this because:
1. I believe that a user will first seek for a command which can
describe a table I) among the db.* commands II) v.db.* III) v.* (v.info
would be the last reasonable place to look for it if I were a newbie,
let's make it easier).

2. I remember one of the goals in Grass>=5.7 was to get rid of doubled
functionality.

Maciek


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