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.
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.
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.
Defining a Data Model
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