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 or directly from the database. When it is created from a layer, ther attributes are be linked to the geometries of that layer. When it is created from a database, it does not have any geometry associated. For selecting data joining tables with the links use `aRTthemes`.

### Objects from the Class

Objects can be created by calling `openTable()` or `createTable()`, from `aRTlayer` of form `aRTdb`.

### Extends

Class `aRTcomponent`, directly.

### Methods

addRows:
  Adds rows to the table.
createColumn:
  Creates a column in the table.
createAndFillColumn:
  Creates a column based on some operation of another layer. It works only with tables of cellular layers.
createRelation:
  Creates a relation between an attribute of the table and an attribute of another table.
getData:
  Returns the table values.
updateColumns:
  Adds columns and(or) update them.

### 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

### See Also

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

[Package aRT version 1.7-1 Index]