This is the command v.db.droprowgrass that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
PROGRAM:
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 inhab >= 10000
output=name [required]
Name for output vector map
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
Use v.db.droprowgrass online using onworks.net services