[GRASS5] Re: [bug #3368] (grass) v.db.addcol manual - what column

[Maciek Sieczka]

>> this bug's URL: http://intevation.de/rt/webrt?serial_num=3368
>> Subject: v.db.addcol manual - what column types?
>>
>> Platform: GNU/Linux/i386
>> grass obtained from: Trento Italy site
>> grass binary for platform: Compiled from Sources
>> GRASS Version: cvs 21.06.2005
>>
>> columns=string
>> name and type of the new columns (ex: col1 type1, col2 type2)
>>
>> is not informative. I still can't create new columns because I don't know
>> what
>> are the types allowed and how to input them here. I bet not only me. So a
>> short note what data types are recognized by Grass and how to call them
>> would
>> do much help. Or maybe that could go to "sql notes"?

L Moritz  Lenert
L I agree that this should be documented.
L Radim, are all types supported by the respective backends supported by
GRASS ?
L If that is the case we could at least insert links to the different
backend's
L websites...
L Moritz

B - Radim Blazek
B The types depend on database which is used.

Facts
1 dbf is a default database driver in Grass, which means that it is most
likely to be used

2 it is almost sure that a Grass newbie will first use the dbf

3 dbf-based examples are most common in Grass manuals (14 manuals,
postgres -10)

4 dbf is the only driver mentioned in "sqlnotes"

... yet the user who wants to start using dbf driver is not informed what
kind of data types are supported.

4 Shapefile, which uses dbf, is widely used for data exchange. In particular
a Grass newbie who is migrating his data from other GIS is very likely to
use Shapefile. Thus the likelyhood of dbf-related problems and doubts
increases.

5 Could we assume that if somebody is using psql or other advanced database
then he automatically knows enough about it all so that he doesn't have such
basic problems? If so, we could conclude that such a basic guiding is only
needed for dbmi amateurs (like me), who are using the default dbf driver.

Maciek