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.