aRTtable {aRT} | R Documentation

## Class aRTtable

### Description

Class that represents a DBMS table. It can be one of the various TerraLib table types.

Tables are created from layers, and their attributes can be linked to other tables or geometries. For selecting data joining tables with the links use aRTthemes.

### Objects from the Class

Objects can be created by calls of the form `new("aRTtable", aRTlayer, tablename, create = T)`

### Arguments

parent:
  Object of class {`aRTlayer`,`aRTdb`}.
tablename:
  Name of the table.
create:
  Can the table be created if it does not exist?
id:
  The name of the unique identifier of the table (default = “id”). Used only at creating.
length:
  The maximum length of id instances. Used only at creating.
generateids:
  Populate the table ids linking with the layer geometries? Used only at creating, and with static and dynamic attributes tables only.
type:
  The type of the table, see below.

### Extends

Class `aRTcomponent`, directly.

### Methods

addColumns:
  Add new columns to the table.
addRows:
  Add new elements to the table.
getData:
  Returns the table values.

### Table types

In TerraLib there are several types of table, implementing the entity relationship, temporal and other models. They are:

static
  Table which each geomety has one, and only one, respective row.
media
  A media table has only two columns: object_id and media_name. It associates an url to a geometry double-click in a TerraLib-based GIS. A layer can have only one media table, and this table does not have a name.
external
  Each row is not implicitly connected to a geometry, but the table can have foreign keys to all static, event and dynamoc tables.
event
  One geometry occours in a specific time interval, as murderers.
dynatt
  Attributes changing in the time, but the objects have static geometry.
alldyn
  Fully dynamic (attributes and geometry). (not implemented yet)
dyngeom
  Dynamic Geometry. (not implemented yet)
default
  The default value depending on the parent. If the class is aRTlayer, default will be static, else (aRTdb) it will be external.

### Author(s)

Pedro Ribeiro de Andrade Neto

### See Also

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

[Package aRT version 0.4-0 Index]