The Structure of the Client Application
Go Up to Understanding Multi-tiered Database Applications
Client applications can invoke exposed server methods. In order to do that, the proxies can be generated out of an active TSQLConnection connected to a DataSnap server.
To the end user, the client application of a multi-tiered application looks and behaves no differently than a two-tiered application that uses cached updates. User interaction takes place through standard data-aware controls that display data from a TClientDataSet component. For detailed information about using the properties, events, and methods of client datasets, see Using Client Datasets.
TClientDataSet fetches data from and applies updates to a provider component, just as in two-tiered applications that use a client dataset with an external provider. For details about providers, see Using a Client Dataset with a Provider.
These connection components are summarized in the following table.
Connection components
| Component | Protocol |
|---|---|
|
dbExpress | |
|
DataSnap | |
|
in memory (local) | |
|
DCOM | |
|
Windows sockets (TCP/IP) | |
|
HTTP | |
|
SOAP (HTTP and XML) |
For more information about using connection components, see Connecting to the Application Server.