Referential integrity: semantic glue for relational database

A teaching tool for classroom presentation of referential integrity in relational database is described. Most existing database software packages can be clas­ sified as rclationally complete in their implementation of relational data structure and manipulation. However, to be fully relational, a third component, called data integrity, must also be completely supported. Data integrity is supported partially by some packages. The authors have designed and implemented a prototype teaching tool which can be used in a classroom environ­ ment to teach and demonstrate the concept of data integrity, especially, referential integrity. This teaching tool is an important supplement to reinforce the theory presented in the lectures as well as a practical means of providing a hands-on component for the students.