Visual knowledge query language as a front-end to relational systems

• Main Authors: SIAU, Keng, TAN, Kok Phuang, CHAN, Hock Chuan
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 1991
• Subjects: Database structures; Entity-relationship; Knowledge abstraction; Relational query languages; Relational systems; Semantic data model; Storage structures; Translation algorithms; Databases and Information Systems; Theory and Algorithms
• Online Access: https://ink.library.smu.edu.sg/sis_research/9595; https://ink.library.smu.edu.sg/context/sis_research/article/10595/viewcontent/Visual_knowledge_query_language_as_a_front_end_to_relational_systems.pdf
• Institution: Singapore Management University

Relational query languages like SQL and QUEL require the users to understand the complex database structure. This is a burden on end users, especially novice end users who access the database on a casual and infrequent basis. To alleviate the need to know the logical database organization, this paper proposes the use of a semantic data model, known as the Enhanced Entity-Relationship (EER) model, as a front-end to the relational systems. A formal, high-level Visual Knowledge Query Language (VKQL) has also been designed for this interface. This language provides for knowledge abstraction as the user communicates only domain knowledge with the system without any implication on the storage structure or search strategies. A translation algorithm is also described in this paper to translate VKQL queries to Standard SQL equivalents.