## 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: $Date$