A graphical relational query language on Apple Macintosh
Thesis DisciplineComputer Science
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
Graphical presentation has been used effectively to reduce complexity long before computers were invented. The Macintosh's user interface is the motivation for this project to design a graphical relational query language to facilitate easy querying. A graphical methodology for expressing queries has been developed and implemented. This thesis explores the pros and cons of alternative approaches for graphical expression of queries and explains the basis for the design of GQL and gives a description of the GQL system itself. In addition to the Macintosh's user interface as an easy to use interaction medium, the GQL system that has been implemented provides further user aids to query formulation. This is achieved by maintaining a local dictionary in which the access path information and predefined subqueries can be permanently stored and used in the formulation of new queries. Another notable feature of GQL is the modular definition of a query, where the module detail can be viewed or hidden using graphical techniques. The design of GQL permits it to be interfaced with any relational DBMS with minimum effort.