A visual query system implementing a temporal object-oriented model with roles on a relational database

The use of a temporal data model to represent an application does not require the existence of a specific database to implement this model. Already-existing commercial databases can be used with an appropriate mapping between data models. When this approach is used, the possibility of stating queries in the original data model is also provided. This paper represents a visual query system for the TF-ORM (Temporal Functionality in Objects-with-Roles Model) data model, which is a temporal object-oriented model with roles. The VQS (Visual Query System) TF-ORM is an environment for information retrieval. Some of its available properties are: visual representation of temporal operators, different level-of-detail definitions when browsing in a graphic scheme, query storage for later use, and the possibility of representing a textual query in a visual way and vice-versa. The TF-ORM model is implemented in a relational database which uses the SQL language for information retrieval. The queries, expressed in the TF-ORM language, are translated into the relational database query language