n--tier sample

mj:

The "Adding and Deleting Entities" learning unit in the 200 Intermediate series includes insert / delete / update functionality with a WinForms front end.

It can be run n-tier with minor adjustments.  You can use the "N-Tier Configuration Starter" tool on the Start / IdeaBlade DevForce / Tools menu to create the client- and server-side configuration files, and to create folders with the files needed for client- and server-side deployment. Then you just launch the ServerConsole.exe program in the Server folder to start the BOS, and you're running n-tier on a single machine (BOS and client app in separate processes).

The part 2 tutorial in the "LINQ, Entity SQL, Deployment Tester", also in 200 Intermediate, steps you through the use of the n-tier configuration starter.

But note that all DevForce apps are logically n-tier, and standard procedure is to retrieve entities to the local cache, modify them locally as desired, create new entities locally, and ultimately save to a back-end datasource.  For this reason, any of our sample solutions can be deployed n-tier with the minor adjustments outlined above.

For new entities created locally, DevForce supplies temporary key values and performs primary and foreign key fixup at save time.  When you delete an entity locally, its DevForce EntityState gets set to EntityState.Deleted; when you then save to the back-end datasource, the deletion is consummated there, and the local entity's EntityState gets set to EntityState.Detached.   It subsequently gets treated as if it did not exist by all client-side operations.

Please let us know if you have further questions.