Abstract: Students studying their first systems learn that many businesses use serial numbers to identify such entities as customers, employees, and products. Sequentially numbered identifiers are prone to substitution and transposition errors during data entry. The addition of a check digit allows a business to continue to use their serial numbers (with modification) and provides identifiers less prone to undetectable data entry errors.

Project oriented systems courses often utilize 4GL tools to implement student designs. With such tools students can reduce the development time considerably over the time required using 3GL procedural programming languages, this allows students to focus on design considerations rather than procedural programming techniques. However, in real life as well as in student projects, some functions cannot be implemented without the use of a procedural language. This article provides instructors material for illustrating how check digits can be incorporated into a microcomputer database application using the procedural language components of two popular database systems.

Keywords: Data validation, Programming, 4GL, 3GL, Check digits, Self-checking numbers

Download this article: JISE - Volume 4 Number 2, Page 17.pdf

Recommended Citation: Hartley, R., Scott, J., & Hayen, R. (1992). Check Digits: Domain Implementation in Microcomputer Databases. Journal of Information Systems Education, 4(2), 17-20.