1grass-mysql(1) GRASS GIS User's Manual grass-mysql(1)
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6 MySQL database driver enables GRASS to store vector attributes in MySQL
7 server.
8 Because vector attribute tables are created automatically when a new
10 vector is written and the name of the table is the same as the name of
11 the vector it is good practice to create a new database for each GRASS
12 mapset.
13
15 A new database is created within MySQL:
16 mysql> CREATE DATABASE mydb;
17 See the MySQL manual for details.
18
20 GRASS modules require 2 parameters to connect to a database. Those pa‐
21 rameters are ’driver’ and ’database’. For MySQL driver the parameter
22 ’driver’ should be set to value ’mysql’. The parameter ’database’ can
23 be given in two formats:
24 • Database name - in case of connection from localhost
26 • String of comma separated list of kye=value options. Supported
28 options are:
29 • dbname - database name
31 • host - host name or IP address
33 • port - server port number
35 Examples of connection parameters:
36 db.connect driver=mysql database=mytest
37 db.connect driver=mysql database=’dbname=mytest,host=test.grass.org’
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40 GRASS supports almost all MySQL data types with following limitations:
41 • Binary columns (BINARY, VARBINARY, TINYBLOB, MEDIUMBLOB, BLOB,
43 LONGBLOB) are not not supported. If a table with binary col‐
44 umn(s) is used in GRASS a warning is printed and only the sup‐
45 ported columns are returned in query results.
46 • Columns of type SET and ENUM are represented as string (VAR‐
48 CHAR).
49 • Very large integers in columns of type BIGINT can be lost or
51 corrupted because GRASS does not support 64 bin integeres on
52 most platforms.
53 • GRASS does not currently distinguish types TIMESTAMP and DATE‐
55 TIME. Both types are in GRASS interpreted as TIMESTAMP.
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58 GRASS modules automatically create index on key column of vector at‐
59 tributes table. The index on key column is important for performance of
60 modules which update the attribute table, for example v.to.db, v.dis‐
61 tance and v.what.rast.
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64 Because MySQL does not support groups of users and because only MySQL
65 ’root’ can grant privileges to other users GRASS cannot automatically
66 grant select privileges on created tables to group of users.
67 If you want to give privilege to read data from your mapset to other
69 users you have to ask your MySQL server administrator to grant select
70 privilege to them on the MySQL database used for that mapset. For exam‐
71 ple, to allow everybody to read data in from your database ’mydb’:
72 shell> mysql --user=root mysql
73 mysql> GRANT SELECT ON mydb.* TO ’’@’%’;
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76 Because MySQL does not support database schemas the parameter ’schema’
77 of module db.connect should never be set to any value. If you set that
78 parameter for MySQL driver GRASS will try to write tables to the speci‐
79 fied schema which will result in errors.
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82 MySQL does not support user groups. Any settings specified by ’group’
83 parameter of module db.connect are ignored by GRASS for MySQL driver.
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86 Attempting to use a reserved SQL word as column or table name will re‐
87 sult in a "SQL syntax" error. The list of reserved words for MySQL can
88 be found in the MySQL manual.
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91 db.connect, SQL support in GRASS GIS
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94 Development of the driver was sponsored by Faunalia (Italy) as part of
95 a project for ATAC.
96
98 Radim Blazek
99 Main index | Topics index | Keywords index | Graphical index | Full in‐
101 dex
102 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
104GRASS 8.2.1 grass-mysql(1)