Subtypes refer to categorizing objects into different subsets within the same dataset based on common attributes. This method enables the classification and management of all objects in a dataset. For example, in a road dataset, different subtypes can be defined based on road types, such as highways, national roads, and provincial roads.

Using subtypes helps maintain data consistency and standardization. By setting corresponding rules and standards for different types of objects, data entry errors can be avoided, and data quality can be improved.

You might use subtypes in the following scenarios:

• Managing the domain and default values of related fields: For each subtype, you can manage the domain and default values of related fields. For example, the "Speed" field of the "Highway" subtype can have its domain set to "Speed Limit" with a default value of "Speed Limit 120," while the "Speed" field of the "National Road" subtype may not have a domain set and only have a default value of "Speed Limit 80."
• Automatic assignment: When editing a subtype field in the attribute table, values are automatically assigned based on the subtype. For example, if the value of the subtype field is updated to "Highway," the default value of the managed "Speed" field will automatically update to "Speed Limit 120."

This chapter will introduce how to manage subtypes.

SuperMap iDesktopX supports this feature starting from the 2025 version.