1databaseintro(1)              Grass User's Manual             databaseintro(1)
2
3
4

Database management in GRASS GIS

6   Attribute management in general
7       GRASS  can be linked to one or many database management systems (DBMS).
8       The db.* set of commands provides basic SQL support for attribute  man‐
9       agement,  while  the  v.db.* set of commands operates on the vector map
10       (see Vector introduction).
11
12   Available drivers
13       Available drivers are listed in SQL support in GRASS GIS.
14
15       Notes:
16       The default DBF driver provides only very limited SQL support  (as  DBF
17       is  not  an  SQL DB) while the other DBMS backends (such as PostgreSQL,
18       MySQL etc) provide full SQL support since the  SQL  commands  are  sent
19       directly to the DBMS.
20
21   DB connection management
22       The  current  database  management  settings are shown or modified with
23       db.connect for current mapset. Available DBMI drivers are  listed  with
24       db.drivers. Some DBMI backends require a user/password for driver/data‐
25       base to be set with db.login.  In order to test a driver, run db.test.
26
27   Attribute data import and export
28       Attribute data can be imported with db.in.ogr from various formats  and
29       exported  with  db.out.ogr. To internally copy a a full table or selec‐
30       tively parts of it, use db.copy.
31
32       Further conversion tools:
33
34                     MDB Tools: Convert MS-Access data to SQL, DBF, etc.
35
36                     Openoffice.org with SQL Databases
37
38   SQL commands
39       GRASS supports to main SQL operations, execution of  an  SQL  statement
40       (db.execute)  and  selection of data from a table (db.select).  See the
41       SQL help page for examples.
42
43   Managing the default DBMI settings
44       Per default vector map attributes are stored in DBF table  files.  This
45       default definition can be modified with db.connect. If an external DBMS
46       is used, db.login may be required.
47
48   Creating a database
49       Specific commands are explained on the individual driver  pages  (these
50       pages are only available if driver was compiled in this installation):
51
52                     DBF: see DBF page
53
54                     SQLite: SQLite page
55
56                     mySQL: meSQL pages
57
58                     ODBC: ODBC page  (connect to Oracle, etc.)
59
60                     PostgreSQL: PostgreSQL and PostGIS page
61
62   Metadata
63       All  columns for a given table are listed with db.columns.  The command
64       db.describe describes a table in detail. To list all  available  tables
65       for a given database, run db.tables.
66
67   Table maintenance
68       To drop a column from a selected attribute table, use db.dropcol.  With
69       db.droptable an attribute table can be deleted.
70
71   Database Schema
72       Currently schema support only works for PostgreSQL connections. Default
73       schema can be set with db.connect. Note that the default schema will be
74       used by all db.* modules.
75
76       db.tables returns 'schema.table' if schemas are available in the  data‐
77       base.
78
79   See also
80                     Introduction to GRASS vector map processing
81
82                     Introduction to GRASS raster map processing
83       Main index - database index - full index
84
85       Last changed: $Date: 2008-02-10 18:09:01 +0100 (Sun, 10 Feb 2008) $
86
87
88
89GRASS 6.3.0                                                   databaseintro(1)
Impressum