v.db.join(1)

NAME
v.db.join

DESCRIPTION
v.db.join joins the content of another table into the connected attribute table of a vector map.

NOTES
v.db.join is a front-end to db.execute to allow easier usage. The vector attribute table must be stored in a SQL database (SQLite, PostgreSQL, MySQL, ODBC, ...). The DBF backend is not supported. Tables can be imported with db.in.ogr.

The vector map-database connection(s) can be verified with v.db.connect.

EXAMPLE
Joining the soil type explanations from table soils_legend into the Spearfish soils map (download legend):
g.copy vect=soils,mysoils
# import legend table
db.in.ogr soils_legend.csv out=soils_legend
# get join column names
v.info -c mysoils
db.describe -c soils_legend
# look at original table
v.db.select mysoils
cat|label
1|Aab
2|Ba
3|Bb
4|BcB
5|BcC
# look at legend
db.select soils_legend
db.select soils_legend | head -7
id|shortname|longname
0|no data|no data
0|AaB|Alice fine sandy loam, 0 to 6
0|Ba|Barnum silt loam
0|Bb|Barnum silt loam, channeled
0|BcB|Boneek silt loam, 2 to 6
0|BcC|Boneek silt loam, 6 to 9
# join soils_legend into mysoils attribute table
v.db.join mysoils col=label otable=soils_legend ocol=shortname
# verification of join
v.db.select mysoils
cat|label|id|shortname|longname
1|Aab|||
2|Ba|2|Ba|Barnum silt loam
3|Bb|3|Bb|Barnum silt loam, channeled
4|BcB|4|BcB|Boneek silt loam, 2 to 6
5|BcC|5|BcC|Boneek silt loam, 6 to 9

SEE ALSO
db.execute, db.in.ogr, v.db.update
GRASS SQL interface

AUTHOR
Markus Neteler

Last changed: $Date: 2011-11-08 10:42:51 +0100 (Tue, 08 Nov 2011) $

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