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Note: A new GRASS GIS stable version has been released: GRASS GIS 7.4, available here.
Updated manual page: here

NAME

v.db.select - Prints vector map attributes.

KEYWORDS

vector, attribute table, database, SQL

SYNOPSIS

v.db.select
v.db.select --help
v.db.select [-rcvf] map=name [layer=string] [columns=name[,name,...]] [where=sql_query] [group=string] [separator=character] [vertical_separator=character] [null_value=string] [file=name] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-r
Print minimal region extent of selected vector features instead of attributes
-c
Do not include column names in output
-v
Vertical output (instead of horizontal)
-f
Exclude attributes not linked to features
--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:

map=name [required]
Name of 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
columns=name[,name,...]
Name of attribute column(s)
where=sql_query
WHERE conditions of SQL statement without 'where' keyword
Example: income < 1000 and inhab >= 10000
group=string
GROUP BY conditions of SQL statement without 'group by' keyword
separator=character
Field separator
Special characters: pipe, comma, space, tab, newline
Default: pipe
vertical_separator=character
Output vertical record separator
Special characters: pipe, comma, space, tab, newline
null_value=string
String representing NULL value
file=name
Name for output file (if omitted or "-" output to stdout)

Table of contents

DESCRIPTION

v.db.select prints attributes of a vector map from one or several user selected attribute table columns.

EXAMPLES

All examples are based on the North Carolina sample dataset.

Select and show entire table

v.db.select map=roadsmajor
cat|MAJORRDS_|ROAD_NAME|MULTILANE|PROPYEAR|OBJECTID|SHAPE_LEN
1|1|NC-50|no|0|1|4825.369405
2|2|NC-50|no|0|2|14392.589058
3|3|NC-98|no|0|3|3212.981242
4|4|NC-50|no|0|4|13391.907552
...

Select and show single column from table

Note: multiple columns can be specified as comma separated list.
v.db.select map=roadsmajor column=ROAD_NAME
NC-50
NC-50
NC-98
NC-50
NC-98
...

Print region extent of selected vector features

v.db.select -r map=roadsmajor where="ROAD_NAME = 'NC-98'"
n=248425.389891
s=245640.640081
w=635906.517653
e=661979.801880

Select empty vector features (no data entries)

v.db.select geonames_wake where="ALTERNATEN IS NULL"
cat|GEONAMEID|NAME|ASCIINAME|ALTERNATEN|FEATURECLA|FEATURECOD|...
8|4498303|West Raleigh|West Raleigh||P|PPL|US||NC|338759|123|...
14|4459467|Cary|Cary||P|PPL|US||NC|103945|146|152|America/Iqaluit|...
31|4452808|Apex|Apex||P|PPL|US||NC|30873|167|134|America/Iqaluit|...
...

Select not empty vector features (no data entries)

v.db.select geonames_wake where="ALTERNATEN IS NOT NULL"
cat|GEONAMEID|NAME|ASCIINAME|ALTERNATEN|FEATURECLA|FEATURECOD|...
9|4487042|Raleigh|Raleigh|Raleigh,...
31299|4487056|Raleigh-Durham Airport|Raleigh-Durham Airport|...
...

Select features with distinct road names

v.db.select map=roadsmajor columns=ROAD_NAME group=ROAD_NAME
ROAD_NAME

I-40
I-440
I-540
NC-231
NC-39
NC-42
...
It is also possible to combine with where option
v.db.select map=roadsmajor columns=ROAD_NAME,MULTILANE group=ROAD_NAME where='ROAD_NAME is not null'
ROAD_NAME|MULTILANE
I-40|yes
I-440|yes
I-540|yes
NC-231|no
NC-39|no
NC-42|no
NC-50|no
NC-54|no
NC-55|no
NC-96|no
NC-97|no
NC-98|no
US-1|
US-401|no
US-64|yes
US-70|yes
It can also use more columns in group option
v.db.select map=roadsmajor columns=ROAD_NAME,MULTILANE group=ROAD_NAME,MULTILANE where='ROAD_NAME is not null'
ROAD_NAME|MULTILANE
I-40|yes
I-440|yes
I-540|yes
NC-231|no
NC-39|no
NC-42|no
NC-50|no
NC-54|no
NC-55|no
NC-96|no
NC-97|no
NC-98|no
US-1|
US-1|yes
US-401|no
US-401|yes
US-64|yes
US-70|yes

SEE ALSO

db.select

AUTHORS

Radim Blazek, ITC-Irst, Trento, Italy
Minimal region extent added by Martin Landa, FBK-irst (formerly ITC-irst), Trento, Italy (2008/08)
Group option added by Luca Delucchi, Fondazione Edmund Mach, Trento, Italy (2015/12)

Last changed: $Date: 2016-10-27 14:24:04 -0700 (Thu, 27 Oct 2016) $

SOURCE CODE

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


Note: A new GRASS GIS stable version has been released: GRASS GIS 7.4, available here.
Updated manual page: here

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© 2003-2018 GRASS Development Team, GRASS GIS 7.2.4svn Reference Manual