The data service layer is responsible for loading data from and storing data into the database. This includes common filtering methods that will be used by multiple client services and/or blocks.

All Data Service Layer classes should reside in the Rock.Model namespace and folder structure inside the Rock project. The Model and ModelService classes should be placed directly in the Rock.Model namespace, but follow the Rock\Model\[Domain]\[Entity]\ folder structure. For instance, ConnectionType and ConnectionTypeService classes go in the Rock.Model namespace, but reside as the files Rock\Model\Connection\ConnectionType\ConnectionType.cs and Rock\Model\Connection\ConnectionType\ConnectionTypeService.cs.

Any additional classes, such as ConnectionTypeQueryOptions, should go in the namespace Rock.Model.Connection.ConnectionType (in the case of this specific class, to follow the Method Behavior Parameters pattern it would go in Rock.Model.Connection.ConnectionType.Options namespace).