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

SEE ALSO

db.droptable, db.execute, v.db.addcolumn, v.db.addtable, v.db.connect, v.db.dropcolumn, v.db.droptable, v.db.select, v.db.update

AUTHOR

Markus Neteler

Last changed: $Date$