- Visual DataFlex
Visual DataFlex is a 4GL windows
programming language by Data Access, targeted at creatingdatabase and client-server type programs.Architecture
Visual DataFlex has a 3-layer architecture:
;Bottom layer: Tables at this level represent customer information. Data dictionaries for each table define the rules for saving, editing, deleting, or finding a customer.
;Middle layer: Tables at this level represent orders to customers. A "Data Dictionary Connectivity Object Tree" defines how tables relate to each other, and ensures that all business rules of the connected tables are in force and validate.
;Top layer: A graphical user interface (
GUI ) that allows users to enter, find, create, modify, or delete data.History
Data Access Worldwide of Miami, USA is the company behind the studio and language and built its business up around the console mode
DataFlex language which was released prior to DOS and competed with DBase2 in early microcomputer technology. The first attempt at a windows product was "DataFlex for Windows" which failed as it was a sort of windows bolted on top of DOS product. Then they released Visual DataFlex 4.0 in 1997 which allowed users to write native 32 bits Windows applications. Every 6 months a new revsion level is released. Visual DataFlex is now in revision 14, named VDF 2008, and features a datadictionary layer of business rules which is of dual use with the windows product and the webapp extension.External links
* [http://www.visualdataflex.com Official website]
* [http://www.vdfwiki.com vdfwiki.com]
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