Creating subtypes

When you create a subtype for a feature class or nonspatial table, you can base the subtype on an existing attribute field or you can add a new field to contain the subtype values. The only stipulation is that your subtype field type must be long or short integer.

To create a subtype, first choose the subtype field, then enter the appropriate code and description. For each subtype, you can associate default field values and domains.

Three subtypes are being created to group stream features.

In the example above, three subtypes have been created for the Watershed feature class. For the Third Order stream subtype, a default value of 1 has been specified for the Contaminants attribute field. Both of the user-defined attribute fields have domains associated with them.

Once you have entered the codes and descriptions for the subtypes, you need to choose one of the subtypes as the default subtype. When you add a new feature in ArcMap, it will automatically be the default subtype and inherit its associated default values and domains. You can change a new feature's subtype after it is created.

When adding default values and domains for a subtype, you can copy the default values and domains from the default subtype.

INFO tables and subtypes

If you want to create subtypes for a nonspatial table that was imported from an INFO table, you can only use a field that was defined as 4-byte binary for the subtype field. If necessary, you can create a new integer field and copy all the values from the existing non-integer field into it.