NAME

       db.execute  - Executes any SQL statement.

KEYWORDS

       database, attribute table, SQL

SYNOPSIS

       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/

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 interface

AUTHOR

       CERL

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

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