Provided by: grass-doc_6.4.3-3_all
db.execute - Executes any SQL statement.
database, attribute table, SQL
db.execute db.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 If not given or '-' read from standard input driver=name Driver name Options: sqlite,mysql,odbc,pg,dbf,ogr Default: dbf database=name Database name Default: $GISDBASE/$LOCATION_NAME/$MAPSET/dbf/
db.execute allows the user to execute SQL statements.
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.
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
db.columns, db.describe, db.drivers, db.droptable, db.login, db.select, db.tables, GRASS SQL interface
CERL Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $ Full index © 2003-2013 GRASS Development Team