Storing data in a DataWindow object using the Data view
Usually you retrieve data into a DataWindow object from the database,
because the data is changeable and you want the latest information. However, sometimes
the data you display in a DataWindow object never changes (as in a list
of states or provinces), and sometimes you need a snapshot of the
data at a certain point in time. In these situations, you can store
the data in the DataWindow object itself. You do not need to go out to
the database or other data source to display the data.
The most common reason to store data in a DataWindow object is for
use as a drop-down DataWindow where the data is not coming from
a database. For example, you might want to display a list of postal
codes for entering values in a State or Province column in a DataWindow object.
You can store those codes in a DataWindow object and use the DropDownDataWindow
edit style for the column.
For more information about using the DropDownDataWindow
edit style, see Chapter 21, “Displaying and Validating
Data “.
To store data in a DataWindow object:
-
If the Data view is not already displayed, select
View>Data from the menu bar.In the default layout for the DataWindow painter, the Data view displays in
a stacked pane under the Properties view. All columns defined for
the DataWindow object are listed at the top. -
Do any of the following:
- Click the Insert Row button in the PainterBar to create an
empty row and type a row of data. You can enter as many rows as
you want. - Click the Retrieve button in the PainterBar to retrieve
all the rows of data from the database. You can delete rows you
do not want to save or manually add new rows. - Click the Delete button in the PainterBar to delete
unwanted rows.
Data changes are local to the DataWindow object Adding or deleting data here does not change the data in the
database. It only determines what data will be stored with the DataWindow object when
you save it. The Update DB button is disabled. - Click the Insert Row button in the PainterBar to create an
-
When you have finished, save the DataWindow object.
When you save the DataWindow object, the data is stored in the DataWindow object.
Sharing data with the Preview view
To see changes you make in the Data view reflected in the
Preview view, select ShareData from the pop-up menu in the Data
view. The Preview
view shows data from the storage buffer associated with the Data
view.
Saving the DataWindow object without data
If you saved the DataWindow object with data to obtain a snapshot,
you usually need to save it again without data. To do so, select
Delete All Rows from the pop-up menu in the Data view before saving.
Sharing DataWindow objects with other developers Storing data in a DataWindow object is a good way to share data and
its definition with other developers. They can simply
open the DataWindow object on their computers to get the data and all its
properties.
What happens at runtime
Data stored in a DataWindow object is stored within the actual object
itself, so when a window opens showing such a DataWindow, the data
is already there. There is no need to issue Retrieve to
get the data.
PowerBuilder never retrieves data into
a drop-down DataWindow that already contains data. For all other DataWindow objects,
if you retrieve data into a DataWindow object stored with data, PowerBuilder handles
it the same as a DataWindow object that is not stored with data: PowerBuilder gets
the latest data by retrieving rows from the database.