v.db.droprow - GRASS GIS manual

Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.

NAME

v.db.droprow - Removes a vector feature from a vector map through attribute selection.

KEYWORDS

vector, attribute table, database

SYNOPSIS

v.db.droprow

v.db.droprow --help

v.db.droprow input=name [layer=string] where=sql_query output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

input=name [required]: Name of input vector map; Or data source for direct OGR access
layer=string: Layer number or name; Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.; Default: 1
where=sql_query [required]: WHERE conditions of SQL statement without 'where' keyword; Example: income < 1000 and population >= 10000
output=name [required]: Name for output vector map

DESCRIPTION
NOTES
EXAMPLES
SEE ALSO
AUTHOR

DESCRIPTION

v.db.droprow removes vector object(s) (point, line, area, face etc.) from a vector map through attribute selection in the table connected to the given vector map. It automatically checks the connection for the specified layer.

NOTES

v.db.droprow is a front-end to v.extract (reverse selection) to allow easier usage. The existing database connection(s) can be verified with v.db.connect.

EXAMPLES

Dropping all vector points without elevation attribute (North Carolina data set):

g.region raster=elevation -p
v.random output=rand5k_elev n=5000 

v.db.addtable map=rand5k_elev column="elevation double precision"
v.what.rast vect=rand5k_elev rast=elevation column=elevation

# verify absence of some elevation attributes ("number of NULL attributes"):
v.univar rand5k_elev type=point column=elevation

# Remove all vector points lacking elevation attribute
v.db.droprow rand5k_elev output=rand5k_elev_filt where="elevation IS NULL"

# verify:
v.univar rand5k_elev_filt type=point column=elevation

AUTHOR

Markus Neteler

SOURCE CODE

Available at: v.db.droprow source code (history)

Latest change: Thursday Feb 03 11:10:06 2022 in commit: 547ff44e6aecfb4c9cbf6a4717fc14e521bec0be