bionic (1) db.execute.1grass.gz

NAME

       db.execute  - Executes any SQL statement.
       For SELECT statements use ’db.select’.

KEYWORDS

       database, attribute table, SQL

SYNOPSIS

       db.execute
       db.execute --help
       db.execute   [-i]    [sql=sql_query]    [input=name]    [driver=name]    [database=name]    [schema=name]
       [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -i
           Ignore SQL errors and continue

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       sql=sql_query
           SQL statement
           Example: update rybniky set kapri = ’hodne’ where kapri = ’malo’

       input=name
           Name of file containing SQL statement(s)
           ’-’ for standard input

       driver=name
           Name of database driver
           Options: dbf, mysql, odbc, ogr, pg, sqlite
           Default: sqlite

       database=name
           Name of database
           Default: $GISDBASE/$LOCATION_NAME/$MAPSET/sqlite/sqlite.db

       schema=name
           Database schema
           Do not use this option if schemas are not supported by driver/database server

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  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 GRASS SQL interface for how to create a new database.

EXAMPLES

       Create a new table with columns ’cat’ and ’soiltype’:
       db.execute sql="CREATE TABLE soils (cat integer, soiltype varchar(10))"
       Create a new table using a file with SQL statements
       db.execute driver=odbc database=grassdb input=file.sql
       Insert new row into attribute table:
       db.execute sql="INSERT INTO mysites (id,name,east,north) values (30,’Ala’,1657340,5072301)"
       Update attribute entries to new value based on SQL rule:
       db.execute sql="UPDATE roads SET travelcost=5 WHERE cat=1"
       Update attribute entries to new value based on SQL rule:
       db.execute sql="UPDATE dourokukan SET testc=50 WHERE testc is NULL"
       Delete selected rows from attribute table:
       db.execute sql="DELETE FROM gsod_stationlist WHERE latitude < -91"
       Add new column to attribute table:
       db.execute sql="ALTER TABLE roads ADD COLUMN length double"
       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 input=-
       Drop column from attribute table:
       db.execute sql="ALTER TABLE roads DROP COLUMN length"
       Drop table (not supported by all drivers):
       db.execute sql="DROP TABLE fmacopy"
       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;
       db.execute input=file.sql
       Join  table  ’myroads’  to  table  ’extratab’  based  on common ’cat’ column values (not supported by DBF
       driver):
       db.execute sql="UPDATE extratab SET names=(SELECT label FROM myroads WHERE extratab.cat=myroads.cat)"

SEE ALSO

        db.columns, db.describe, db.drivers, db.droptable, db.login, db.select, db.tables,

        GRASS SQL interface

AUTHOR

       CERL

       Last changed: $Date: 2014-11-28 10:57:47 +0100 (Fri, 28 Nov 2014) $

SOURCE CODE

       Available at: db.execute source code (history)

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       © 2003-2018 GRASS Development Team, GRASS GIS 7.4.0 Reference Manual