Visual FoxPro, or VFP, is a programming language and IDE that was sold by Microsoft, but is now defunct. The primary use of the language is for rapid database application development. The programming syntax is similar to that of Visual BASIC (not VB.NET). The language uses dynamic inferred structural typing. It compiles to pseudo-code which is interpreted by the runtimes which must be distributed along with the program.
Visual FoxPro is based off of FoxPro, which was the result of Microsoft buying FoxBase from Fox Software. FoxBase was derived from dBase III. The last official release of Visual FoxPro was version 9, which was released in 2004 with a final service pack released in 2007. Microsoft officially discontinued support in 2015, most likely because it was taking away sales of from SQL Server, which was far more expensive.
Though I had seen FoxPro icons since my first days with Windows 3, I never knew what FoxPro was. I got my first taste of Visual FoxPro in 1999 because it was the main programming language used by the company I started working for. I was familiar with Visual BASIC, so it was pretty easy for me to pickup the syntax, and I had just developed an Access application for my high school, so I knew enough about databases to secure my job. I've used VFP from version 6 until its final release, version 9.0 SP2.
- The IDE has a bunch of built-in editors for databases, forms, reports, menus, and more. Though none of them aren't without their problems, it's one of the most complete I've ever used.
- The IDE uses an vastly superior MDI (multiple document interface) instead of the inferior, and, unfortunately, now industry standard, TDI (tabbed document interface). Unlike in a TDI, you can easily open and view several different code segments and designers at the same time. You can even open multiple widows from the same code source which is extremely helpful, something I wish every other IDE would adopt (I'm looking at you Visual Studio).
- It has a full SQL interpreter as well as many additional database features not found even in modern databases, and they're very easy to use.
- The SQL speed is lightning fast, and highly optimization, even to the point of outpacing many other professional SQL programs.
- Some of the table field types are quite useful like the currency with 4-digit decimal precision, and the numeric which is based on length of digits rather than bytes.
- Unlike most earlier versions of Visual BASIC, VFP had several built-in variable types like datetime and logical with assorted functions to work with them.
- The database format is way out of date and doesn't support any modern formats like Unicode.
- Numeric variables (and likewise, table fields) are divorced from most other languages. There is no support for unsigned values at all, and there are no primitive types like byte, int, long, etc. Instead, all numbers are treated as either signed double integers or floats, and even then, their type is always implied.
- Functions that affect file names like Copy File don't preserve text case.
- The UI tries to remember the position of windows and the code block you last viewed, but usually fails.
- Although VFP is mostly object oriented, it has a lot of legacy commands and functions that are procedural. This lack of standards creates confusion.
- While text fields longer than 254 characters are possible, they require the use of "memos" which are especially cumbersome to work with.
- VFP's help has a poor index which is missing dozens of commands. For example, Type "ALEN" in the Index tab and you get a page for "_ALen() API library routine," but there isn't an entry for the ALEN() Function, even though a page exists and can be found in the Search tab.
- VFP's help is seriously lacking on SQL examples and only shows you the most basic of queries.
- VFP has really poor ActiveX and OLE support, often to the point of crashing the UI.
- VFP has really poor array support and only supports 2D arrays (to resemble tables). Single dimensional arrays and arrays with three or more dimensions are not possible.