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Bonus
Day

Day 22

Using PowerBuilder
with an Oracle
Database

This Bonus Day deals with the use of PowerBuilder and Oracle. PowerBuilder is an application-development environment that can be compared to Oracle Power Objects. It is the principal product of Powersoft, a wholly owned subsidiary of Sybase.

PowerBuilder's features include:

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NOTE
The examples in this lesson are based on PowerBuilder Enterprise Edition. To learn more about PowerBuilder, visit the Powersoft Web site at www.powersoft.com.

Like Developer/2000 and Power Objects, PowerBuilder uses a scripting language named PowerScript for event-driven programming. Each object has a set of predefined events for which you can write a script. This script is executed when the event is triggered by an external event—for example, a user pressing Delete—or by another object's script. In addition, you can define additional events for an object and invoke PowerBuilder's comprehensive set of built-in functions from an event script.

Today, you will look at three specific areas:

Defining a Database Profile

The first phase in using PowerBuilder with an Oracle database is setting up a database profile.

  1. Open the PowerBuilder application in which you want to add the database profile.
  2. To add a database profile, click on the DB Profile icon on the toolbar (it looks like four green cylinders). A window will appear, displaying the existing database profiles (see Figure 22.1).
  3. Click on New to add a database profile. The Database Profile Setup window will appear.
  4. Enter Flugle in the Profile Name field (see Figure 22.2).
  5. In the DBMS field, select the current version of your database. This example shows O72 ORACLE v7.2 from the dropdown list (see Figure 22.2).
  6. Click on More to specify the other fields for the Oracle database profile.

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Figure 22.1.
The Database Profiles
window displays
existing database
profiles.

Figure 22.2.
Specifying the Profile
Name and DBMS for
the new database
profile.

NOTE
If you do not see your current version in the dropdown list, you may need to reinstall some components. During the installation of PowerBuilder Enterprise Edition, you can select Typical or Custom installation options. The Typical installation option will not install the current version's native database driver. If you are using Windows 95 or Windows NT, you must be using SQL*Net V2.2 or above, and you must install the Oracle 7.x or higher's PowerBuilder native database driver.

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  1. If you are connecting to an Oracle server, enter the database alias that you use in the Server Name field. If you are using Personal Oracle, leave this field blank.
  2. In Login ID, enter the Oracle username that you want to use for accessing the database.
  3. In Login Password, enter the password for the Oracle user, as displayed in
    Figure 22.3.

Figure 22.3.
Specifying the Server
Name, Login ID, and
Login Password for
the new database
profile.

  1. Click OK. PowerBuilder will create the database profile and display it in the list of available profiles (see Figure 22.4).

Figure 22.4.
The new database
profile is displayed in
the list of database
profiles.

  1. After you've created the new database profile, you will see it displayed in the list of available database profiles. To use the database profile, select it and click OK.

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NOTE
The first time you create a database profile for an Oracle database, PowerBuilder tries to create a repository—a set of five tables that are used to store additional information about each table's columns, such as format or validation. The tables are PBCATCOL, PBCATEDT, PBCATFMT, PBCATTBL, and PBCATVLD.
By default, PowerBuilder tries to create these tables in the Oracle SYSTEM account. Normally, PowerBuilder will return an Oracle error ORA-01031, insufficient privileges, if the Oracle user specified in Login ID doesn't have the privilege to create a table in the SYSTEM account.
There are a couple ways to create the repository if it doesn't already exist. You can create the new database profile and specify SYSTEM for Login ID and the SYSTEM password for Login Password. From SQL*Plus or SQL Worksheet, you then can grant the SELECT, INSERT, UPDATE, and DELETE privileges on the five repository tables to the Oracle user that you want to specify in Login ID.

Creating a DataWindow

To create a new DataWindow, follow these steps:

  1. Click the Datawindow button on the toolbar (it looks like a form and is the ninth button from the left). A window, labeled Select DataWindow, will appear, displaying all the existing DataWindows for the application (see Figure 22.5).
  2. Click New to create a new DataWindow. You will then see the New Datawindow window.
  3. You must make two choices for the New DataWindow—its data source and presentation style. Choose SQL Select for the data source and Tabular for the presentation style (see Figure 22.6).
  4. Click OK.

Another window, labeled Select Tables, will appear. By default, this window will display all the tables that are accessible to the Oracle user associated with the current database profile. This list of tables will include tables owned by other Oracle users. Scroll down to the STUDENT table and click Open (see Figure 22.7).

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Используются технологии uCoz