Manage Subtypes

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

Before using subtypes, please note the following constraints:

  • Subtypes can only be created in datasets containing integer fields.
  • Only applicable to PostGIS and UDBX data sources. Other data sources are temporarily unsupported in the current version.
  • Subtype attributes cannot be copied or exported and will be lost after operations.

Access subtype management via Workspace Manager -> Vector Dataset (e.g., point, line, polygon, or attribute table) context menu -> Attribute Management -> Subtype button.

Create Subtypes

Creating subtypes is a fundamental operation in subtype management, enabling categorical data organization in datasets.

Using a road dataset (attribute structure shown below) as an example to demonstrate subtype creation:

Figure: Attribute Structure of Road Dataset
  1. Click Workspace Manager -> "Road" dataset context menu -> Attribute Management -> Subtype button to open Subtype tab and Subtype Editor window.
  2. Click Subtype tab -> Manage group -> Subtype Management button (or in Subtype Editor window, select radio button in first column to choose "road type" field as subtype field (only integer fields are selectable)) to open Subtype Management dialog.
  3. In Subtype Management dialog, configure subtype information through these steps:
    1. Select Subtype Field: Choose target field from Subtype Field dropdown (e.g., "road type"). Non-integer fields are filtered out.
    2. Set Default Subtype: The first subtype in list becomes default (e.g., "Expressway") after entering codes and descriptions.
    3. Add Subtypes: Two methods available:
      • Manual Entry: Click Add button, input code and description in new row. As shown below, six subtypes are added: "Expressway", "National Highway", "Provincial Highway", "County Road", "Township Road", and "Village Road".
        Figure: Create New Subtypes
      • Auto-Generate: Click Automatically generated button to generate codes and descriptions based on existing field values. Verify accuracy against management requirements.
  4. Click OK, then click Subtype tab -> Manage group -> Save button to save subtypes to dataset.
  5. View Creation Results:
    • Adding "Road" dataset to map window automatically generates unique value thematic map based on subtypes.
    • Open attribute table to display field values using subtype descriptions. Subtype icon appears in column headers.
    • In dataset properties, icon precedes "road type" field, indicating it's a subtype field with editable alias only.

Edit Selected Fields in Subtype Management

In Subtype Editor window, directly edit Range and default values of managed fields to ensure compliance with updated requirements.

Example: For "Expressway" subtype, default value of "Speed Limit" field is "120 km/h", and "Road Material" field has Range "Asphalt"; "National Highway" subtype manages "Speed Limit" field with default value "80 km/h".

Figure: Subtype Editor Window

After saving via Subtype tab -> Manage group -> Save button, edit "road type" values in attribute table (select from dropdown). Related fields auto-update with default values. E.g., setting "road type" to "Expressway" updates "Speed Limit" to "120 km/h" and "Road Material" to "Asphalt".

Modify Subtypes

Modifying subtypes involves updating existing subtype information and adjusting managed fields, ensuring datasets adapt to evolving requirements while maintaining data integrity.

  1. Click Subtype tab -> Manage group -> Subtype Management button to open dialog. Editable items include:
    • Change Subtype Field: Select new integer field from Subtype Field dropdown.
    • Modify Default Subtype: Choose new default from dropdown.
    • Add Subtypes: Use Add button or Automatically generated to create new entries.
    • Edit Subtypes: Double-click code or description cells to modify values directly.
    • Delete Subtypes: Select records and click Delete.
      Note:

      At least one subtype must remain after selecting a field. To clear all subtypes, choose Clear All Subtypes from Subtype Field dropdown.

  2. Click Subtype tab -> Manage group -> Save to commit changes.

Related Topics

Subtype Overview

Domain