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

       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

        GRASS SQL interface

AUTHOR

       Markus Neteler

SOURCE CODE

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

       Accessed: Friday Apr 04 01:21:13 2025

       Main index | Vector index | Topics index | Keywords index | Graphical index | Full index

       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                                 v.db.droprow(1grass)