Example: printing data from a DataStore

Suppose you have a window called w_employees that allows users to retrieve, update, and print employee data retrieved from the database:

The picture shows a group box with radio button options at the top of a window titled Employee, and a Data Window at the bottom of the window. The Employee List radio button is selected in the Options group box. The sample Data Window object displayed in the Data Window control has three columns with the headings Department, Name, and Salary.

The DataWindow object displayed in the DataWindow control is suitable for online display but not for printing. In this case, you could define a second DataWindow object for printing that has the same result set description as the object used for display and assign the second object to a DataStore. You could then share data between the DataStore and the DataWindow control. Whenever the user asked to print the data in the window, you could print the contents of the DataStore.

Required third-party software You must install the FieldSoftware PrinterCE SDK before you can use print methods in PocketBuilder applications deployed to a device or emulator. An evaluation version of this software is available from the FieldSoftware Web site.

When the window or form opens

The code you write begins by establishing the hand pointer as the current row indicator for the dw_employees DataWindow control. Then the script sets the transaction object for dw_employees and issues a Retrieve method to retrieve some data. After retrieving data, the script creates a DataStore using the instance variable or data member ids_datastore, and assigns the DataWindow object d_employees to the DataStore. The final statement of the script shares the result set for the dw_employees DataWindow control with the DataStore.

This code is for the window’s Open event:

dw_employees.SetRowFocusIndicator(Hand!)

dw_employees.SetTransObject(SQLCA)

dw_employees.Retrieve()

ids_datastore = CREATE datastore

ids_datastore.DataObject = "d_employees"

dw_employees.ShareData(ids_datastore)

Code for the Update button

Code for the cb_update button applies the update operation to the dw_employees DataWindow control.

This code is for the Update button’s Clicked event:

IF dw_employees.Update() = 1 THEN

		COMMIT using SQLCA;

		MessageBox("Save","Save succeeded")

ELSE

		ROLLBACK using SQLCA;

		MessageBox("Save","Save failed")

END IF

Code for the Print button

The Clicked event of the cb_print button prints the contents of ids_datastore. Because the DataWindow object for the DataStore is d_employees, the printed output uses the presentation specified for this object.

This code is for the Print button’s Clicked event:

ids_datastore.Print()

When the window or form closes

When the window closes, the DataStore gets destroyed.

This code is for the window’s Close event:

destroy ids_datastore