Rechercher une page de manuel
db.execute.1grass
Langue: en
Version: 335976 (ubuntu - 24/10/10)
Section: 1 (Commandes utilisateur)
NAME
db.execute - Executes any SQL statement.KEYWORDS
database, attribute table, SQLSYNOPSIS
db.executedb.execute help
db.execute [-i] [input=name] [driver=name] [database=name] [--verbose] [--quiet]
Flags:
- -i
Ignore SQL errors and continue- --verbose
Verbose module output- --quiet
Quiet module output
Parameters:
- input=name
Name of file containing SQL statements- driver=name
Driver name
Options: dbf,odbc,pg,mysql,sqlite,ogr
Default: dbf- database=name
Database name
Default: $GISDBASE/$LOCATION_NAME/$MAPSET/dbf/
DESCRIPTION
db.execute allows the user to execute SQL statements.NOTES
db.execute only executes SQL statements and does not return any data. If you need data returned from the database, use db.select.If parameters for database connection are already set with db.connect, they are taken as default values and do not need to be specified each time.
If you have a large number of SQL commands to process, it is much much faster to place all the SQL statements into a text file and use db.execute's input file parameter than it is to process each statement individually in a loop. If multiple instruction lines are given, each SQL line must end with a semicolon.
Please see the individual sql driver pages for how to create a new database.
EXAMPLES
Create a new table with columns 'cat' and 'soiltype':echo 'create table soils (cat integer, soiltype varchar(10) )' | db.execute
Create a new table using a file with SQL statements:
db.execute driver=odbc database=g60test input=file.sql
Insert new row into attribute table:
echo "INSERT INTO nobugs (id,name,east_gb,north_gb) values (30,'Ala',1657340,5072301)" | db.execute
Update attribute entries to new value based on SQL rule:
echo "UPDATE roads SET travelcost=5 WHERE cat=1" | db.execute
Update attribute entries to new value based on SQL rule:
echo "UPDATE dourokukan SET testc=50 WHERE testc is NULL" | db.execute
Delete selected rows from attribute table:
echo "DELETE FROM gsod_stationlist WHERE latitude < -91" | db.execute
Add new column to attribute table:
echo "ALTER TABLE roads ADD COLUMN length double" | db.execute
Column type conversion - update new column from existing column (all drivers except for DBF):
# 'z_value' is varchar and 'z' is double precision:
echo "update geodetic_pts SET z = CAST(z_value AS numeric)" | db.execute
Drop column from attribute table:
echo "ALTER TABLE roads DROP COLUMN length" | db.execute
Drop table (not supported by all drivers)
echo "DROP TABLE fmacopy" | db.execute
Update attribute with multiple SQL instructions in file (e.g., file.sql, instruction line must end with a semicolon):
UPDATE roads SET travelcost=5 WHERE cat=1;
UPDATE roads SET travelcost=2 WHERE cat=2;
cat file.sql | db.execute
Join table 'myroads' into table 'extratab' based on common 'cat' column values (not supported by DBF driver):
echo "UPDATE extratab SET names=(SELECT label FROM myroads WHERE extratab.cat=myroads.cat);" | db.execute
SEE ALSO
db.columns, db.describe, db.drivers, db.droptable, db.login, db.select, db.tables, GRASS SQL interfaceAUTHOR
CERLLast changed: $Date: 2008-11-26 20:30:58 +0100 (mer, 26 nov 2008) $
Full index
© 2003-2010 GRASS Development Team
Contenus ©2006-2024 Benjamin Poulain
Design ©2006-2024 Maxime Vantorre