Database management in GRASS GIS
Attribute management in general
GRASS can be linked to one or many database management systems (DBMS).
The db.* set of commands provides basic SQL support for
attribute management, while the v.db.* set of commands operates
on the vector map (see Vector introduction).
Available drivers
Available drivers are listed in SQL support in GRASS GIS.
Notes:
The default DBF driver provides only very limited SQL
support (as DBF is not an SQL DB) while the other DBMS backends (such
as PostgreSQL, MySQL etc) provide full SQL support since the SQL
commands are sent directly to the DBMS.
SQL commands
SQL commands can be directly executed with
db.execute, db.select
and the other db.* modules.
See the SQL help page for examples.
Managing the default settings
Per default vector map attributes are stored in DBF table files. This default
definition can be modified with db.connect. If an
external DBMS is used, db.login may be required.
Creating a database
Specific commands are explained on the individual driver pages (these
pages are only available if driver was compiled in this installation):
Conversion tools:
MDB Tools:
Convert MS-Access data to SQL, DBF, etc.
Example:
Database Schema
Currently schema support only works for PostgreSQL connections. Default schema
can be set with db.connect. Note that the default
schema will be used by all db.* modules.
db.tables returns 'schema.table' if schemas are
available in the database.
See also
Main index -
database index -
full index
Last changed: $Date: 2006/08/24 19:11:36 $