BTW, in my quest to move into the Windows world, I actually bought a copy way back in 1995 and attended a 5-day Training by the renowned Clipper Guru, Rick Spence in Kuala Lumpur, Malaysia. That was before I discovered Delphi.
As I understand it, CA-VO development was taken over by GrafX Software Development and the latest version is 2.8 released on 15th May 2007
Visual Objects includes support for Clipper based DBF files including those using the NTX, CDX, and MDX indexing methods via Replaceable Database Driver (RDD) technology.
Visual Objects features a structured superset of the Xbase language. (Xbase is the industry standard term for those programming languages that inherit from the original dBASE system, including CA-Clipper, CA-dBFast, the dBASE family of products, and FoxPro.)
The Xbase superset contains extensions for Windows and its environment, including the ability to access all Win32 Application Programming Interface (API) functions for low-level, system programming.
Open Database AccessVisual Objects gives you a wide variety of choices in terms of database access. It supports:
- Both procedural and object-oriented access to Xbase databases
Visual Objects supports the procedural database commands and functions—such as SKIP and EOF()—that are traditional to Xbase languages.
It also includes, however, an object-oriented interface to Xbase database management. The object-oriented interface is akin, semantically and syntactically, to the commands and functions traditionally used in procedural access. Instead of commands like APPEND, COMMIT, and ZAP, for example, you will use methods named Append(), Commit(), and Zap() to perform the same operation.
Note: With these new methods, all the capabilities of the traditional Xbase approach are provided, but have been enhanced to fit the event-driven, multi-tasking nature of GUI applications.
- Access to both Xbase and SQL databases
When using an object-oriented approach to database management, both Xbase and SQL databases can be accessed. Furthermore, access to these two different types of databases is accomplished using a single, compatible protocol. This allows an application to manage Xbase and SQL databases with the same code.
- Several different Xbase/SQL database formats
When accessing Xbase databases (using either a procedural or object-oriented approach), you can choose from a variety of file formats. This is accomplished through replaceable database driver (RDD) technology. With RDDs, a single application can access different database file formats using a common language interface. This allows you to tailor your applications so that migrating from one database format to another is simple and straightforward.
Visual Objects supplies several popular RDDs, and through its open architecture allows for development of third-party RDDs. See the Replaceable Database Drivers section in the “Using DBF Files” chapter in the Programmer’s Guide for more information about RDD technology. Refer to the “RDD Specifics” appendix in the same volume for detailed information about specific RDDs.
Similarly, support for SQL databases is accomplished using Open Database Connectivity (ODBC), a widely used API for SQL access under Windows. This technology also uses replaceable drivers, supplied as dynamic link libraries (DLLs), which standardize the interface to the various database formats. Visual Objects comes bundled with DLLs for many of the popular ODBC formats, and provides language support for a superset of the standard ODBC API, as well as, an object-oriented interface compatible with that used for Xbase database files.