There are a couple of other options for this topic.

If you are simply wanting the ability to define the name of the "ID" field yourself, you can use the class keyword SqlRowidName.  For example:

      SqlRowIdName = PersonId

For an Identity property, there is a way to allow a process to explicitly specify values for the identity property/field.  This is typically useful when first populating a table/object from an external source and you want to retain the identity's values. 

The call is:   set oldValue = $SYSTEM.SQL.SetIdentityInsert(1,.sc)

For more information on the $SYSTEM.SQL.SetIdentityInsert call see class documentation for the %SYSTEM.SQL class.

Here is an example: