Class aRTdb

Description

Class that manipulates a database. Data is stored in layers (geometries and their attributes) or external tables (attributes not directly connected with geometries). aRTdb objects consume more memory then any other object of this package, because it stores all themes, layers and table definitions, and these objects store just a pointer to its “father”. We recommend to work with only one object of this class per time.

Objects from the Class

Objects can be created by calls of the form new("aRTdb", aRTconn, dbname, create). To avoid creating objects this way, there are two functions of class aRTconn: createDb and openDb.

Arguments

aRTconn

Object of aRTconn class.

dbname

Database name.

create

Create a new database when create=TRUE, and open a existing database when create=FALSE. The default is create=FALSE.

Extends

Class aRTcomponent, directly.

Methods

createLayer:

Creates a new layer returns it.

createView:

Creates an empty View in the database.

deleteLayer:

Delete a layer in the database.

deleteTheme:

Delete a theme in the database.

deleteView:

Delete a view in the database.

importShape:

Imports a shapefile to the database.

openLayer:

Opens an existent layer.

openTheme:

Opens an existent theme. (Themes can be created only from layers.)

showLayers:

Shows all the available layers.

showThemes:

Shows all the available themes.

showViews:

Show all the available views.

summary:

Some information about the database.

Environments

An aRTenv is the set of themes and views of a user in a TerraLib database. Layers in a database are visible by all users that have read permission in the database, but each user has it owns views and themes. Therefore it can be useful to manipulate a user's environment, as for example save in a file, load and remove.

aRTloadEnv, aRTsaveEnv, aRTclearEnv, aRTgetEnv and aRTremoveEnv manipulate environments without any aRT object as argument.

Views are only destinate to TerraView users. It has no importance inside R.

Author(s)

Marcos Aurelio Carrero, Pedro Ribeiro de Andrade Neto

See Also

See aRTdb-METHOD for a method of this class or CLASSNAME-class for links to other classes.