.TH v.db.droprow 1grass "" "GRASS 7.8.5" "GRASS GIS User's Manual"
.SH NAME
\fI\fBv.db.droprow\fR\fR  \- Removes a vector feature from a vector map through attribute selection.
.SH KEYWORDS
vector, attribute table, database
.SH SYNOPSIS
\fBv.db.droprow\fR
.br
\fBv.db.droprow \-\-help\fR
.br
\fBv.db.droprow\fR \fBinput\fR=\fIname\fR  [\fBlayer\fR=\fIstring\fR]  \fBwhere\fR=\fIsql_query\fR \fBoutput\fR=\fIname\fR  [\-\-\fBoverwrite\fR]  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-help\fR" 4m
.br
Print usage summary
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.IP "\fB\-\-ui\fR" 4m
.br
Force launching GUI dialog
.SS Parameters:
.IP "\fBinput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of input vector map
.br
Or data source for direct OGR access
.IP "\fBlayer\fR=\fIstring\fR" 4m
.br
Layer number or name
.br
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.
.br
Default: \fI1\fR
.IP "\fBwhere\fR=\fIsql_query\fR \fB[required]\fR" 4m
.br
WHERE conditions of SQL statement without \(cqwhere\(cq keyword
.br
Example: income < 1000 and population >= 10000
.IP "\fBoutput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name for output vector map
.SH DESCRIPTION
\fIv.db.droprow\fR 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.
.SH NOTES
v.db.droprow is a front\-end to \fIv.extract\fR (reverse selection)
to allow easier usage.
The existing database connection(s) can be verified with \fIv.db.connect\fR.
.SH EXAMPLES
Dropping all vector points without elevation attribute (North Carolina data set):
.br
.br
.nf
\fC
g.region raster=elevation \-p
v.random output=rand5k_elev n=5000
v.db.addtable map=rand5k_elev column=\(dqelevation double precision\(dq
v.what.rast vect=rand5k_elev rast=elevation column=elevation
# verify absence of some elevation attributes (\(dqnumber of NULL attributes\(dq):
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=\(dqelevation IS NULL\(dq
# verify:
v.univar rand5k_elev_filt type=point column=elevation
\fR
.fi
.SH SEE ALSO
\fI
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
\fR
.SH AUTHOR
Markus Neteler
.SH SOURCE CODE
.PP
Available at: v.db.droprow source code (history)
.PP
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.PP
© 2003\-2020
GRASS Development Team,
GRASS GIS 7.8.5 Reference Manual