expand-select

In contrast to the OData v2 implementation, you have to select and expand separately. In other words, selected properties are not expanded automatically as in v2.

The reason for this difference originates in the way select and expand work in OData v4. In OData v4 you select within the expand-argument $expand=Friends($select=FirstName) whereas in OData v2 you select via a path $select=Friends/FirstName&$expand=Friends. That's why we mimic this behavior for select and expand operations in our API for OData v4 type-safe client.

People.requestBuilder()
  .getAll()
  .select(People.LAST_NAME)
  .expand(People.FRIENDS.select(People.FIRST_NAME, People.ADDRESS_INFO));

In the example above you select the LAST_NAME of the root entity and expand the navigation property FRIENDS. In the expanded entity the selected fields are FIRST_NAME and ADDRESS_INFO.

The generated URL for this request will be:

/People?$select=LastName&$expand=Friends($select=FirstName,AddressInfo)

If no select is given, all non-navigational properties are included in the response.