Features

The PowerBuilder DataWindow control is a container for DataWindow
objects in a PowerBuilder application. You can use it in a window
to present an interactive display of data. The user can view and
change data and send changes to the database.

In addition to the DataWindow control, the DataStore object
provides a nonvisual container for server applications and other
situations where on–screen viewing is not necessary.

The DataWindow supports data retrieval with retrieval arguments
and data update. You can use edit styles, display formats, and validation
rules for consistent data entry and display. The DataWindow provides
many methods for manipulating the DataWindow, including Modify for
changing DataWindow object properties. You can share a result set
between several DataWindow controls and you can synchronize data
between a client and server.

Development environment

You can develop both parts of your DataWindow implementation
in PowerBuilder. You use:

• The DataWindow painter
  to define DataWindow objects.

• The Window or User Object painters to add DataWindow
  controls to windows or visual user objects. The DataWindow control
  is on the drop–down palette of controls for these painters.

  In the Window or User Object painters, you can write scripts
  that control the DataWindow’s behavior and manipulate the
  data it retrieves. Your scripts can also instantiate DataStore objects.

In the PowerBuilder Browser you can examine the properties,
events, and methods of DataWindow controls and DataStore objects
on the System tab page. If you have a library open that contains
DataWindow objects, you can examine the internal properties of the
DataWindow object on the Browser’s DataWindow tab page.

DataWindow objects

The DataWindow control or DataStore object uses a DataWindow
object defined with any presentation style. The DataWindow object
determines what data is retrieved and how it is displayed. The control
can also display Powersoft reports (PSRs), which do not need to
retrieve data.

Database connections

The PowerBuilder DataWindow can use ODBC, JDBC, and native
database drivers for database connectivity. Users can connect to
a data source on any server to which they have access, including
databases and middle-tier servers on the Internet.

To make a connection, you can use the internal Transaction
object of the DataWindow, or you can make the connection with a
separate PowerBuilder transaction object.

A PowerBuilder application provides a default Transaction
object, SQLCA. You can define
additional Transaction objects if you need to make additional connections.
When you connect with a separate Transaction object, you can control
when SQL COMMIT and ROLLBACK
statements occur, and you can use the same connection for multiple
controls.

For more information about using a Transaction
object with a DataWindow, see Chapter 2, “Using DataWindow Objects.”

For more information about PowerBuilder Transaction
objects, see Application Techniques in the
PowerBuilder documentation set.

Coding

You write scripts in the Window or User Object painter to
connect to the database, retrieve data, process user input, and
update data.

In PowerBuilder, you can take advantage of object inheritance
by defining a user object inherited from a DataWindow control and
adding your own custom functionality. You can reuse the customized
DataWindow control throughout your applications.

You create DataStore objects, the nonvisual version of a DataWindow
control, by creating them in a script and calling methods for the
object. You can also define a user object that is inherited from
a DataStore and customize it. For more information, see Chapter 4, “Using DataStore Objects .”

Libraries and applications

You store DataWindow objects in PowerBuilder libraries (PBLs) during development. When you
build your application, you can include the DataWindow objects in
the application executable or in PowerBuilder dynamic libraries
(PBDs).

For more information about designing DataWindow objects and
building a PowerBuilder application, see the PowerBuilder
Users Guide and Application Techniques.