Accessing a database from an EAServer component

You can access a database from an EAServer component. If you want to take advantage of EAServer’s support for connection pooling and transaction management, you need to use one of the database interfaces supported by EAServer to connect to your database. For more information about EAServer database connections for components developed in PowerBuilder, see Connecting to Your Database.

EAServer components developed in PowerBuilder can use DataStores to interact with the database. DataStores are nonvisual DataWindow controls. DataStores act just like DataWindow controls except that they do not have visual attributes.

DataStores can be useful in a distributed application: they give you the ability to perform database processing on a remote server instead of on each client machine.

If you want to provide a visual interface to the data retrieved on the server, include a window in the client that has a DataWindow control. Whenever data is retrieved on the server, refresh the DataWindow control to show the result set for the DataStore on the server. Similarly, whenever the user makes modifications to the data on the client, refresh the contents of the DataStore on the server to reflect the current state of the DataWindow control on the client.

To share data between a client and a server, synchronize the server DataStore and the client DataWindow control programmatically. If you want your application to handle database updates, this involves moving the DataWindow data buffers and status flags back and forth between the client and the server.