“But wait!”, you say. “Visual FoxPro already has a data dictionary! Why are you complicating my life with another data dictionary?”
Glad you asked. Here’s why you need the Data Builder:
· Complete Application Data Dictionary: A professional database application should have a complete application data dictionary. Visual FoxPro provides a basic data dictionary, but it does not provide a complete application data dictionary. Visual FoxPro does not provide one place you can go to find all information about all data in an application. Visual FoxPro only stores data dictionary information about the tables and views you place in a Visual FoxPro DataBase Container (DBC). The information stored in the DBC is limited. The VPM Enterprise Data Builder, on the other hand, provides one place to store and retrieve information about all the CursorAdapter libraries, CursorAdapters, databases, database tables, views and free tables in your application. The Data Builder provides a complete application data dictionary.
· Extended Table and Field Properties: A professional database application data dictionary needs to store more information about data than is stored in the Visual FoxPro DataBase Container. The chapters that follow describe the additional properties and functionality found in the Data Builder that are not in the DBC.
· CursorAdapter Support: The VPM Enterprise Data Builder provides the same data dictionary support for CursorAdapters that Visual FoxPro provides for tables in a DBC. In fact, VPME provides much more support for CursorAdapters than VFP provides for tables in a DBC.
· Free Table Support: The VPM Enterprise Data Builder provides the same table and field properties and functionality for free tables that Visual FoxPro provides for tables in a DBC. Many FoxPro developers need to create Visual FoxPro applications that use the same data tables as FoxPro 2.6 DOS and Windows applications. That means that the tables the Visual FoxPro application uses must be free tables in the FoxPro 2.6 format. Because Visual FoxPro does not provide data dictionary support for free tables, a developer who must use free tables doesn’t enjoy the benefits of the Visual FoxPro DBC. VPM Enterprise, however, brings the benefits of a data dictionary to free tables as well as tables in a DBC.
Tip: Visual FoxPro does not change the structure of FoxPro 2.6 tables unless you add the table to a database or add a new data type or enable acceptance of null values. Therefore, if you must use a table with both Visual FoxPro and FoxPro 2.6 applications, be sure that you don’t do anything to convert it to the Visual FoxPro structure. If you do, your FoxPro 2.6 applications can’t read it.
· Referential Integrity for Compound Keys: Visual FoxPro does not provide referential integrity for tables linked by compound keys. VPM Enterprise does. You set up referential integrity for your tables, views and CursorAdapters on the Fields - Integrity page in the Data Builder.
· Trans-Database Functionality: With the Data Builder you can set up relations and referential integrity among tables and views in different DBC’s. You can’t do that with Visual FoxPro alone.
· One Interface: The VPM Enterprise Data Builder provides one place to go to view and work on your application’s data dictionary data. In Visual FoxPro you must to go to several places to access all the data information that the Data Builder provides in one spot. You’ll love the ease of access to data information that the Data Builder gives you.
· Easy Program Access: As you will see when you read further, you can easily retrieve the data dictionary information stored in the Data Builder tables if you need to use it programmatically. Data dictionary information is not so easily accessed programmatically from a Visual FoxPro DBC.
· Platform Independence: The VPM Enterprise Data Builder is independent of the Visual FoxPro DataBase Container. The VPM Enterprise Data Builder is platform independent, which provides the following advantages for you:
· VFP Version Changes: New versions of Visual FoxPro that significantly change the DBC will not render your VPM Enterprise applications obsolete overnight. Your VPME applications can be used with a new VFP version without reprogramming the links to the data dictionary.
· New VPME Platforms: We have had many requests to develop versions of ProMatrix for other platforms, such as Visual Basic, Visual J++, Access, Delphi and Power Builder. If we do, your VPME application’s data dictionary would be easily transportable to the new platform because the Data Builder is independent of the development platform on which it resides.
So, you can see that even though Visual FoxPro provides a “starter” data dictionary, a professional database application needs much more. The VPM Enterprise Data Builder provides the additional application data dictionary information that’s needed.
Tip – Use the Data Builder: Before you use a database, table, local view, remote view or CursorAdapter in your VPME application, create it in the Data Builder or add it to the Data Builder if it already exists. Enter the table, view, CursorAdapter and field properties in the Data Builder. Then, when you use the VPME form classes, control classes and builders to create forms, the properties in the Data Builder will be used to help automate form creation. When you run a form, the table, view, CursorAdapter and field properties in the Data Builder let the form and its controls know how to work.