Collection Generation

The user can define an objects collection which is a set of all objects in the category. Whenever a cadastral IL is active, the Query... button is enabled on the " Control Panel" and if you click on it, the " Generating and Selecting Collections" window will be presented. Even if the user does not want to define a specific collection, he must go through this interface and choose ALL to perform the query.

A collection is defined for only one object category,even if the active IL has more than one. There are two different ways to do it:

Defining the collection considering the category attributes from the selected object, for instance, "generate a collection of the object Farms that have areas greater than 2.500 ha";
Defining the collection by drawing a rectangle using the Zoom Cursor ( atalho_cursor_ar.gif - 923 Bytes): all entities (points, lines or polygons) that are inside this rectangle will be considered.

NOTE: The system stores the definition of all collections in a table called "collections", and the objects in tables with the same name of each collection. See the instructions below:


Creating a collection of an object attribute:

  • activate a cadastral IL which has data to be queried;
  • click on Query... on the " Control Panel". The " Generating and Selecting Collections" window is presented;
  • type a name for the collection on the field Collectionand click on Create;
  • on the Attributes list, choose one and clique on it. Observe that the Logical Expression field presents the result of your choice;
  • click on an Operation ( = , < > , > , < , >= , <= );
  • type in a value for the selected attribute and click CR, or use the Value buttons: T (All), E (edges) or N (none) to see the list of values and to then select one;
  • use one of the buttons ( ), AND, OR, ( or ) to continue typing the expression;
  • click on Generate after defining the query expression;
  • click on Apply to select the collection. The windows "Visualizing Objects" and " Table" are presented.

Creating a collection using the Zoom Cursor:

  • activate a cadastral IL which has data to be queried;
  • click on Query... on the " Control Panel". The " Generating and Selecting Collections" window is presented;
  • type a name for the collection on the field Collectionand click on Create;
  • click on View - Zoom Cursor( atalho_cursor_ar.gif - 923 Bytes) on the main menu to activate it and define a rectangle as if you were performing a zoom. Click on a top left point and then on a bottom right point to involve the entities you want.
  • click on Area: With cursor after having defined the rectangle. The X and Y coordinates will be updated;
  • click on Generate after defining the query expression;
  • click on Apply to select the collection. The windows "Visualizing Objects" and " Table" are presented.


Applying an already defined collection:

  • activate a cadastral IL which has data to be queried;
  • click on Query... on the " Control Panel". The " Generating and Selecting Collections" window is presented;
  • select on the Objects Categories list the want you want. Sometimes the associated IL has a single category and this one will be available on the list;
  • select on the Collections list the one you want. The option ALL will always be available;
  • click on Apply to activate the collection. The "Visualizing Objects" and " Table" windows will be presented.

OBS: To delete a collection you should repeat the four first steps above and then click onDelete.

See also:

Database Query
How to control Objects Visualization .
Attributes Query.
Spatial Query
Attributes Table.
Pointing and Photo Module.

Query Models.