A visual data model

摘要

The Visual Data Model VDM and the Visual Data Language VDL are introduced. They provide a unique approach to modelling and manipulating data through spatial arrangement of geometric objects. They are based on the functional data model and the clausal form of the first order logic; however all data and all database activities are represented spatially using geometric objects such as arcs, rectangles and circles. The representation is aimed at the nonprofessional office users. The objective is to perform in the office all database activities including modelling, retrieval, integrity enforcement, transaction management and data derivation.