Manage Subtypes

Provides the Subtype tab and Subtype Editing window for creating, modifying, and deleting subtypes.

Before using subtypes, you should note the following limitations:

  • Subtypes can only be created in datasets containing integer fields.
  • Only applicable to PostGIS and UDBX data sources; the current version does not support other data sources.
  • Subtype attributes are not exportable and will be lost after the operation completes.

You can access subtype management via Workspace Manager → context menu of vector datasets (e.g., point, line, polygon, or attribute table datasets) → Attribute Management → Subtype button.

Create Subtypes

Creating subtypes is a fundamental operation in subtype management, used to add subtypes to datasets for categorized data management. If a field already has a range set, creating a subtype will override the original range, rendering the prior domain settings invalid.

Using a road dataset (attribute structure shown below) as an example to create subtypes, this section describes how to create subtypes:

Figure: Road Dataset Properties Structure
  1. Click Workspace Manager → context menu of the "Road" dataset → Attribute Management → Subtype button to open the Subtype tab and Subtype Editing window.
  2. Click the Subtype tab → Manage group → Subtype Management button (or in the Subtype Editing window, select the radio button in the first column to choose an integer field like "road type" as the subtype field) to open the Subtype Management dialog.
  3. In the Subtype Management dialog, configure subtype information as follows:
    1. Select Subtype Field: From the Subtype Field dropdown, choose the field to create subtypes for (e.g., "road type"). Non-integer fields are filtered out, only integer fields are displayed.
    2. Set Default Subtype: After providing codes and descriptions in the subtype list, the first subtype is used as the Default Subtype by default (e.g., "Highway" here).
    3. Add Subtype: Two methods are available:
      • Manual Addition: Click the Add button, then enter code values and corresponding descriptions in new rows. For example, as shown below, six subtypes are added: "Highway", "National Road", "Provincial Road", "County Road", "Township Road", and "Village Road".
        Figure: Create Subtypes
      • Automatically Generated: Click the Automatically generated button to generate code values and descriptions based on existing field values. Note that you must verify if the generated information accurately reflects your management needs.
  4. After completing the above steps, click the OK button, then click the Subtype tab → Manage group → Save button to save subtype information to the dataset.
  5. View the created subtypes:
    • Add the "Road" dataset to the map window; a unique value thematic map is automatically created based on subtypes.
    • Open the attribute table of the "Road" dataset; subtype descriptions are used to display field values. A subtype icon appears in the table header.
    • When viewing dataset properties, an icon appears before the "road type" field, indicating it is a subtype field where only field aliases are editable.

Edit Select Fields in Subtype Management

In the Subtype Editing window, directly edit the Range and default values of fields in subtype management to ensure they meet current requirements or standards. Each subtype's range configuration applies independently and overrides the original domain settings of the field.

For example, the "Highway" subtype sets the default value of the "Speed Limit" field to "120 km/h" and the Range of the "Pavement Material" field to "Asphalt" with a default value of "Asphalt". The "National Road" subtype only manages the "Speed Limit" field with a default value of "80 km/h".

Figure: Subtype Editing Window

After clicking the Subtype tab → Manage group → Save button to save changes, edit the "road type" field value in the "Road" attribute table (double-click the cell and select a subtype from the dropdown menu). Related field values automatically update to default values. For instance, setting "road type" to "Highway" updates the "Speed Limit" field to "120 km/h" and the "Pavement Material" field to "Asphalt".

Modify Subtypes

Modifying subtypes involves further operations on datasets with existing subtypes, including updating subtype information and adjusting select fields in subtype management. This ensures datasets can adapt flexibly to changing needs, maintaining the effectiveness and accuracy of data management and analysis.

  1. Click the Subtype tab → Manage group → Subtype Management button to open the Subtype Management dialog. Modifiable items include:
    • Switch subtype field: Select another integer field as the new subtype field from the Subtype Field dropdown menu.
    • Modify default subtype: Choose a new default subtype value from the Default Subtype dropdown menu to update the current setting.
    • Add subtype: Use the Add button to manually input new subtype codes and descriptions, or click Automatically generated to quickly create subtypes based on existing field values.
    • Modify subtype: Double-click the code or description cell of a subtype record to make it editable, then directly modify the code or description.
    • Delete subtype: Select the subtype record to delete, then click the Delete button to remove it.
      Note:

      After selecting a field in Subtype Field, at least one subtype record must remain in the list. To clear all subtype information, select Clear All Subtypes from the Subtype Field dropdown menu.

  2. Click the Subtype tab → Manage group → Save button to save changes to the dataset.

Related Topics

Subtype Overview

Range