Database connectivity

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.

Using DataStores

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.

RichText presentation style is not supported

A server component
cannot contain a DataStore that has a DataWindow object that uses
the RichText presentation style. Rich text processing is not supported in
distributed applications.

Sharing data between the server and the client

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.

For more information about synchronizing a server DataStore
with a client DataWindow, see “Performing
updates”.

ShareData function is not supported in distributed
applications

You cannot use the ShareData function to
share data between a DataWindow control on a client and a DataStore
on a server.