1v.db.select(1)              GRASS GIS User's Manual             v.db.select(1)
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NAME

6       v.db.select  - Prints vector map attributes.
7

KEYWORDS

9       vector, attribute table, database, SQL
10

SYNOPSIS

12       v.db.select
13       v.db.select --help
14       v.db.select      [-rcvf]      map=name       [layer=string]       [col‐
15       umns=name[,name,...]]   [where=sql_query]    [group=string]    [separa‐
16       tor=character]    [vertical_separator=character]    [null_value=string]
17       [file=name]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]
18
19   Flags:
20       -r
21           Print minimal region extent of selected vector features instead  of
22           attributes
23
24       -c
25           Do not include column names in output
26
27       -v
28           Vertical output (instead of horizontal)
29
30       -f
31           Exclude attributes not linked to features
32
33       --overwrite
34           Allow output files to overwrite existing files
35
36       --help
37           Print usage summary
38
39       --verbose
40           Verbose module output
41
42       --quiet
43           Quiet module output
44
45       --ui
46           Force launching GUI dialog
47
48   Parameters:
49       map=name [required]
50           Name of vector map
51           Or data source for direct OGR access
52
53       layer=string
54           Layer number or name
55           Vector  features can have category values in different layers. This
56           number determines which layer to use. When  used  with  direct  OGR
57           access this is the layer name.
58           Default: 1
59
60       columns=name[,name,...]
61           Name of attribute column(s)
62
63       where=sql_query
64           WHERE conditions of SQL statement without ’where’ keyword
65           Example: income < 1000 and population >= 10000
66
67       group=string
68           GROUP BY conditions of SQL statement without ’group by’ keyword
69
70       separator=character
71           Field separator
72           Special characters: pipe, comma, space, tab, newline
73           Default: pipe
74
75       vertical_separator=character
76           Output vertical record separator
77           Special characters: pipe, comma, space, tab, newline
78
79       null_value=string
80           String representing NULL value
81
82       file=name
83           Name for output file (if omitted or "-" output to stdout)
84

DESCRIPTION

86       v.db.select  prints attributes of a vector map from one or several user
87       selected attribute table columns.
88

EXAMPLES

90       All examples are based on the North Carolina sample dataset.
91
92   Select and show entire table
93       v.db.select map=roadsmajor
94       cat|MAJORRDS_|ROAD_NAME|MULTILANE|PROPYEAR|OBJECTID|SHAPE_LEN
95       1|1|NC-50|no|0|1|4825.369405
96       2|2|NC-50|no|0|2|14392.589058
97       3|3|NC-98|no|0|3|3212.981242
98       4|4|NC-50|no|0|4|13391.907552
99       ...
100
101   Select and show single column from table
102       Note: multiple columns can be specified as comma separated list.
103       v.db.select map=roadsmajor column=ROAD_NAME
104       NC-50
105       NC-50
106       NC-98
107       NC-50
108       NC-98
109       ...
110
111   Print region extent of selected vector features
112       v.db.select -r map=roadsmajor where="ROAD_NAME = ’NC-98’"
113       n=248425.389891
114       s=245640.640081
115       w=635906.517653
116       e=661979.801880
117
118   Select empty vector features (no data entries)
119       v.db.select geonames_wake where="ALTERNATEN IS NULL"
120       cat|GEONAMEID|NAME|ASCIINAME|ALTERNATEN|FEATURECLA|FEATURECOD|...
121       8|4498303|West Raleigh|West Raleigh||P|PPL|US||NC|338759|123|...
122       14|4459467|Cary|Cary||P|PPL|US||NC|103945|146|152|America/Iqaluit|...
123       31|4452808|Apex|Apex||P|PPL|US||NC|30873|167|134|America/Iqaluit|...
124       ...
125
126   Select not empty vector features (no data entries)
127       v.db.select geonames_wake where="ALTERNATEN IS NOT NULL"
128       cat|GEONAMEID|NAME|ASCIINAME|ALTERNATEN|FEATURECLA|FEATURECOD|...
129       9|4487042|Raleigh|Raleigh|Raleigh,...
130       31299|4487056|Raleigh-Durham Airport|Raleigh-Durham Airport|...
131       ...
132
133   Select features with distinct road names
134       v.db.select map=roadsmajor columns=ROAD_NAME group=ROAD_NAME
135       ROAD_NAME
136       I-40
137       I-440
138       I-540
139       NC-231
140       NC-39
141       NC-42
142       ...
143       It is also possible to combine with where option
144       v.db.select map=roadsmajor columns=ROAD_NAME,MULTILANE group=ROAD_NAME where=’ROAD_NAME is not null’
145       ROAD_NAME|MULTILANE
146       I-40|yes
147       I-440|yes
148       I-540|yes
149       NC-231|no
150       NC-39|no
151       NC-42|no
152       NC-50|no
153       NC-54|no
154       NC-55|no
155       NC-96|no
156       NC-97|no
157       NC-98|no
158       US-1|
159       US-401|no
160       US-64|yes
161       US-70|yes
162       It can also use more columns in group option
163       v.db.select map=roadsmajor columns=ROAD_NAME,MULTILANE group=ROAD_NAME,MULTILANE where=’ROAD_NAME is not null’
164       ROAD_NAME|MULTILANE
165       I-40|yes
166       I-440|yes
167       I-540|yes
168       NC-231|no
169       NC-39|no
170       NC-42|no
171       NC-50|no
172       NC-54|no
173       NC-55|no
174       NC-96|no
175       NC-97|no
176       NC-98|no
177       US-1|
178       US-1|yes
179       US-401|no
180       US-401|yes
181       US-64|yes
182       US-70|yes
183

SEE ALSO

185        db.select
186

AUTHORS

188       Radim Blazek, ITC-Irst, Trento, Italy
189       Minimal  region  extent  added  by  Martin  Landa,  FBK-irst  (formerly
190       ITC-irst), Trento, Italy (2008/08)
191       Group  option  added  by Luca Delucchi, Fondazione Edmund Mach, Trento,
192       Italy (2015/12)
193

SOURCE CODE

195       Available at: v.db.select source code (history)
196
197       Main index | Vector index | Topics index | Keywords index  |  Graphical
198       index | Full index
199
200       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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204GRASS 7.8.5                                                     v.db.select(1)
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