GRASS GIS manual: v.db.addtable

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NAME

v.db.addtable - Creates and connects a new attribute table to a given layer of an existing vector map.

KEYWORDS

vector, database, attribute table

SYNOPSIS

v.db.addtable
v.db.addtable help
v.db.addtable map=name [table=string] [layer=integer] [columns=name type[,name type,...]] [--verbose] [--quiet]

Parameters:

map=name: Vector map for which to add new attribute table
table=string: Name of new attribute table (default: vector map name)
layer=integer: Layer where to add new attribute table; Default: 1
columns=name type[,name type,...]: Name and type of the new column(s) (types depend on database backend, but all support VARCHAR(), INT, DOUBLE PRECISION and DATE); Default: cat integer

DESCRIPTION

v.db.addtable creates and adds a new attribute table to a given vector map. It links the table to the specified layer of the vector map. If the vector map is not yet linked to any table, new a database link is established based on the MAPSET database settings (see db.connect).

NOTES

v.db.addtable is a front-end to db.execute to allow easier usage. v.db.addtable will only insert category values into the table for those features which actually have a category value in the relevant layer. The use can add category values automatically by using v.category or manually with wxGUI vector digitizer before running v.db.addtable. Or one can run v.db.addtable first and then use either a combinatino of v.category + v.to.db or wxGUI vector digitizer to add the relevant lines to the table. The supported types of columns depend on the database backend. However, all backends should support VARCHAR, INT, DOUBLE PRECISION and DATE.

The existing database connection(s) can be verified with v.db.connect.

EXAMPLE

Adding a new attribute table with a single column to default layer 1:

g.copy vect=roadsmajor,myroads
v.db.addtable myroads columns="slope double precision"
v.db.connect -p myroads
v.info -c myroads

Adding a new attribute table with two columns to layer 2:

g.copy vect=roadsmajor,myroads
v.db.addtable myroads columns="slope double precision, roadname varchar(15)" layer=2
v.db.connect -p myroads
v.info -c myroads
v.info -c myroads layer=2

AUTHOR

Markus Neteler

Last changed: $Date: 2012-11-25 05:27:13 -0800 (Sun, 25 Nov 2012) $

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