1grass-mysql(1) Grass User's Manual grass-mysql(1)
2MySQL driver in GRASS MySQL database driver in GRASS enables GRASS to store
6vector attributes in MySQL server.
7 Because vector attribute tables are created automaticaly when a new
9 vector is written and the name of the table is the same as the name of
10 the vector it is good practice to create a new database for each GRASS
11 mapset.
12
14 A new database is created within MySQL:
15 mysql> CREATE DATABASE mydb;
16 See the MySQL manual for details.
17
19 GRASS modules require 2 parameters to connect to a database. Those
20 parameters are 'driver' and 'database'. For MySQL driver the parameter
21 'driver' should be set to value 'mysql'. The parameter 'database' can
22 be given in two formats:
23 Database name - in case of connection from localhost
25 String of comma separated list of kye=value options.
27 Supported options are:
28 dbname - database name
30 host - host name or IP address
32 port - server port number
34 Examples of connection parameters:
35 db.connect driver=mysql database=mytest
36 db.connect driver=mysql database='dbname=mytest,host=test.grass.org'
37
40 GRASS supports almost all MySQL data types with following limitations:
41 Binary columns (BINARY, VARBINARY, TINYBLOB, MEDIUMBLOB,
43 BLOB, LONGBLOB) are not not supported. If a table with
44 binary column(s) is used in GRASS a warning is printed
45 and only the supported columns are returned in query
46 results.
47 Columns of type SET and ENUM are represented as string
49 (VARCHAR).
50 Very large integers in columns of type BIGINT can be
52 lost or corrupted because GRASS does not support 64 bin
53 integeres on most platforms.
54 GRASS does not currently distinguish types TIMESTAMP and
56 DATETIME. Both types are in GRASS interpreted as TIME‐
57 STAMP.
58
60 GRASS modules automaticaly create index on key column of vector
61 attributes table. The index on key column is important for performance
62 of modules which update the attribute table, for example v.to.db,
63 v.distance and v.what.rast.
64
66 Because MySQL does not support groups of users and because only MySQL
67 'root' can grant privileges to other users GRASS cannot automaticaly
68 grant select privileges on created tables to group of users.
69 If you want to give privilege to read data from your mapset to other
71 users you have to ask your MySQL server administrator to grant select
72 privilege to them on the MySQL database used for that mapset. For exam‐
73 ple, to allow everybody to read data in from your database 'mydb':
74 shell> mysql --user=root mysql
76 mysql> GRANT SELECT ON mydb.* TO ''@'%';
77
80 Because MySQL does not support database schemas the parameter ’schema'
81 of module db.connect should never be set to any value. If you set that
82 parameter for MySQL driver GRASS will try to write tables to the speci‐
83 fied schema which will result in errors.
84
86 MySQL does not support user groups. Any settings specified by 'group'
87 parameter of module db.connect are ignored by GRASS for MySQL driver.
88
90 SQL support in GRASS GIS
91
93 Development of the driver was sponsored by Faunalia (htttp://www.fauna‐
94 lia.it) as part of a project for ATAC (http://www.atac.roma.it/).
95
97 Radim Blazek
98 Last changed: $Date: 2006/08/24 19:11:36 $
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101GRASS 6.2.2 grass-mysql(1)