1v.db.droprow(1) GRASS GIS User's Manual v.db.droprow(1)
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6 v.db.droprow - Removes a vector feature from a vector map through at‐
7 tribute selection.
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10 vector, attribute table, database
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13 v.db.droprow
14 v.db.droprow --help
15 v.db.droprow input=name [layer=string] where=sql_query output=name
16 [--overwrite] [--help] [--verbose] [--quiet] [--ui]
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18 Flags:
19 --overwrite
20 Allow output files to overwrite existing files
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22 --help
23 Print usage summary
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25 --verbose
26 Verbose module output
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28 --quiet
29 Quiet module output
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31 --ui
32 Force launching GUI dialog
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34 Parameters:
35 input=name [required]
36 Name of input vector map
37 Or data source for direct OGR access
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39 layer=string
40 Layer number or name
41 Vector features can have category values in different layers. This
42 number determines which layer to use. When used with direct OGR ac‐
43 cess this is the layer name.
44 Default: 1
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46 where=sql_query [required]
47 WHERE conditions of SQL statement without ’where’ keyword
48 Example: income < 1000 and population >= 10000
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50 output=name [required]
51 Name for output vector map
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54 v.db.droprow removes vector object(s) (point, line, area, face etc.)
55 from a vector map through attribute selection in the table connected to
56 the given vector map. It automatically checks the connection for the
57 specified layer.
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60 v.db.droprow is a front-end to v.extract (reverse selection) to allow
61 easier usage. The existing database connection(s) can be verified with
62 v.db.connect.
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65 Dropping all vector points without elevation attribute (North Carolina
66 data set):
67 g.region raster=elevation -p
68 v.random output=rand5k_elev n=5000
69 v.db.addtable map=rand5k_elev column="elevation double precision"
70 v.what.rast vect=rand5k_elev rast=elevation column=elevation
71 # verify absence of some elevation attributes ("number of NULL attributes"):
72 v.univar rand5k_elev type=point column=elevation
73 # Remove all vector points lacking elevation attribute
74 v.db.droprow rand5k_elev output=rand5k_elev_filt where="elevation IS NULL"
75 # verify:
76 v.univar rand5k_elev_filt type=point column=elevation
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79 db.droptable, db.execute, v.db.addcolumn, v.db.addtable, v.db.connect,
80 v.db.dropcolumn, v.db.droptable, v.db.select, v.db.update
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82 GRASS SQL interface
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85 Markus Neteler
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88 Available at: v.db.droprow source code (history)
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90 Accessed: Mon Jun 20 16:47:45 2022
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92 Main index | Vector index | Topics index | Keywords index | Graphical
93 index | Full index
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95 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
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99GRASS 8.2.0 v.db.droprow(1)