v.db.addcolumn.1grass - Man Page

Adds one or more columns to the attribute table connected to a given vector map.

Keywords

vector, attribute table, database

Synopsis

v.db.addcolumn
v.db.addcolumn --help
v.db.addcolumn map=name  [layer=string]  columns=name type[,name type,...]  [--help]  [--verbose]  [--quiet]  [--ui]

Flags

--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 where to add column(s)
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 type[,name type,...] [required]

Name and type of the new column(s) (’name type [,name type, ...]’)
Types depend on database backend, but all support VARCHAR(), INT, DOUBLE PRECISION and DATE. Example: ’label varchar(250), value integer’

Description

v.db.addcolumn adds one or more column(s) to the attribute table connected to a given vector map. It automatically checks the connection for the specified layer.

Notes

v.db.addcolumn is a front-end to db.execute to allow easier usage. 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.

Examples

Adding a single column:

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

Adding two columns:

g.copy vect=roadsmajor,myroads
v.db.addcolumn myroads columns="slope double precision,myname varchar(15)"
v.info -c myroads

See Also

db.connect, db.execute, v.db.addtable, v.db.connect, v.db.dropcolumn, v.db.droptable, v.db.select, v.db.update

GRASS SQL interface

Author

Moritz Lennert (mlennert@club.worldonline.be)

Source Code

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

Accessed: Saturday Nov 09 07:56:31 2024

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