Defining a Data Model

To add data into SPRING it is required to define the different types of data that will be handled, that is, to define the Database model.

Defining a Data Model in the Database is simply to specify the Categories and Classes (for a thematic data model), plus the data attributes and graphical presentation characteristics (Visual) of the objects or just the non-spatial tables.

In the SPRING, any map has to belong to a Category, that is, it has to belong to one of the following types Thematic, Numerical, or Image, if the data type is field; Network or Cadastral (object maps) , if the data type is object with its descriptive attributes, or even, Non-spatial, if the data type is an alphanumeric table.

See also:


The available models are:

IMAGE

The Image Category model is related to the matrix format used in remote sensing systems. Examples: TM/LANDSAT, SPOT, NOAA, images, aerial pictures converted into digital images though scanners, etc.

NUMERICAL

The Numerical Category model is related to data that has a continuous variation of its values as a function of its ground position. Examples: altimetry, soil Ph, magnetometry, soil temperature, etc.

THEMATIC

The Thematic Category model is related to data that classifies a geographical position using a certain theme. Examples: soil types, vegetation type, etc.

CLASSES

When using the thematic model it is required to define the Thematic Classes, which are category specializations. Taking as an example a category type soil, each different soil type will be a class. For example, "latossolo roxo", "podzolico e litossolo".

OBJECT

The Object Category model is related to a geographical object specialization. Example: cities, streets, houses etc.

CADASTRAL

The Cadastral Category model is related to maps with a certain object representation, example: political division (cadastral category that shows a map with city representations).

NETWORK

The Network Category model is related to geographical data that has a flow and connection relations among the several elements one wants to have monitored and represented. Example: electrical network, water and sewerage distribution networks, telephone networks, etc.

NON-SPATIAL

The Non-spatial Category model is related to data that has no spatial relationships as, for instance, urban cadastral/registration data.


The data graphical presentation characteristics are also defined and stored with the Database model. The Visual term is used in the Spring system to define the areas, lines, points and texts characteristics for a category/class in the Database.

When modeling the Database Tables are defined to insert, store and retrieve the data descriptive attributes. Each Category has a unique Attributes' table where fields are defined by the user. The attributes editing and analysis resources are available only for the Object and Non-Spatial category model.

IMPORTANT: After inserting alphanumerical data in an object or a non-spatial table it is not possible to add new attributes using the Spring system because the procedures required for checking data consistency and data integrity are not integrated in the system yet. If any structural change is required the user has to use the Database manager available for the table. See more details in "How to edit filled tables ? ".



See also:
How to define the Visual aspects for a thematic Class or Category ?
How to define attributes for a thematic Class or Category
What is a project in the Spring system and how to create a project ?
About the SPRING Conceptual Model




Creating a Category or Class

Category

The category concept put together the same type of data in the Database, defining a data class. Each category is always associated to a unique data model and may have several Information Layers in different projects but in the same Database. The Information Layer can only be created once a Category was created.

For the non-spatial data model it is required to define a table's name. An attribute's table in the Dbase 4 format can be automatically related to the Spring Database if the table's name is properly informed and the table is defined in the Spring Database directory.

Creating categories before using them does not mean that the user has to define them all at once. Usually, tables are created when they are required in a project.

Creating Categories:

  • click in File - Data Model... in the main menu or in icon;
  • select the Model type you want to create: Image, DTM, Thematic, Object, Cadastral, Network or Non-Spatial;
  • define the category's Name. The category's name may have up to 32 characters, including blanks or special characters, such as:! @ # $ % ^ & * ( ) - + = | \ { [ }] : ; " ',< > / or ?;
  • define the attribute's Table name for a Non-Spatial Category;
  • click in Create, - repeat the last three steps if you want to create other categories;
  • click in Apply to create the categories in the Database.



Thematic Classes

For the Thematic Model it is required to create Thematic Classes. We will see also that it is possible to define a unique non-spatial attributes' table for all thematic classes. In the Soils Category example, for each class, we can define attributes such as texture, granulometry, color, pH etc.


Creating Thematic Classes:

  • select from the Categories list a thematic model item;
  • select Thematic Classes tab.
  • give the class Name. The name may have up to 32 characters, including blanks;
  • click in Create to add a class in the list;
  • click in Apply so the classes will be added to the Database. Once a class is created it can not be removed from the Database but the class name and the class visual aspects can be changed.

IMPORTANT: Before clicking the Apply button it is possible to remove a class from the list; simply click the Delete button.


NOTE: At any time the user can come back to the "Data Model" window and add new classes or even change the name and visual aspects of the existing ones.

After creating a category you can define a data graphical presentation characteristics, which are also defined and stored with the Database directory. Click in Visual... to define the areas, lines, points and texts characteristics or the thematic classes in an active Database.

See also:
How to create a project.
How to create a Database.
How to create an Information Layer.
How to create a Category or Class Attribute.


Seta_a3.gif - 268 Bytes Defining the Data Model


Changing a Category or Class

This option is only available for changing a Category or Class name .

Changing a Category or Class:

  • click on the Category or Class name in the list. Notice that the name field is selected;
  • change the name in the text box;
  • click in Change. Notice that the name also changes in the list;
  • click in Apply so the changes will be performed in the Database directory.


See also:
How to change a Project.
How to change an Information Layer.


Seta_a3.gif - 268 Bytes Defining the Data Model


Deleting a Category or Class

A Category can only be deleted if there is no information associated to it. For the Image, Cadastral, Thematic, Numerical (DTM) or Network categories it is not possible to have an Information Layer associated to it. For the thematic category the classes associated will be also removed. For the object category it not possible to have one or more associated objects. For the non-spatial category it is not allowed to have an external connection in the data base. In this SPRING version a class can only be deleted from the Database if it is not created in the Database yet.

Deleting a Category or Class:

  • click on the Category or Class name in the list. Notice that the Name field is selected;
  • click in Delete. The system will display a message if there is any data associated to the category.


See also:
How to delete a Project.
How to delete a Database.
How to delete an Information Layer.
How to delete a Thematic Category or Class Attribute.


Seta_a3.gif - 268 Bytes Defining a Data Model