'''Visual DataFlex''' is a 4GL windows [[programming language]] by [[Data Access (company)|Data Access]], targeted at creating [[database]] 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==
{{Cleanup-section|date=February 2008}}
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.
