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: Tuesday Jun 27 11:14:34 2023

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

       © 2003-2023 GRASS Development Team, GRASS GIS 8.3.0 Reference Manual