Scaling Up to a Three-tiered Application
Go Up to Building Multi-tiered Applications
In a two-tiered client/server application, the application is a client that talks directly to a database server. Even so, the application can be thought of as having two parts: a database connection and a user interface. To make a two-tiered client/server application into a multi-tiered application you must:
- Split your existing application into an application server that handles the database connection, and into a client application that contains the user interface.
- Add an interface between the client and the application server.
There are a number of ways to proceed, but the following sequential steps may best keep your translation work to a minimum:
- 1. Create a new project for the application server, duplicate the relevant database connection portions of your former two-tiered application, and for each dataset, add a provider component that will act as a data conduit between the application server and the client.
- 2. Copy your existing two-tiered project, remove its direct database connections, add an appropriate connection component to it.
- 3. Substitute a client dataset for each dataset component in the original project.
- 4. In the client application, add code to apply updates to the application server.
- 5. Move the dataset components to the application server’s data modules. Set the
DataSetproperty of each provider to specify the corresponding datasets.