This is the first in a series of database design case studies. Consisting of just two tables, it is the most basic case presented.
The secretary for the Canadian Vintage Motorcycle Group has asked you to design an Access database for the club.
The club needs to print a club roster which includes the names, addresses, and telephone numbers of all its members as well as the make, model, and year of each member's vintage motorcycles.
Design a suitable database and diagram it to show the fields (including keys), the tables, and the relationships between the tables.
The first step in database design is to determine all the necessary fields and segregate them into groups that mirror the natural order of the real world.
When the fields have been grouped into their natural order, each group represents a table.
Each record in a table must be uniquely identified by its value in the table's key field.
The next step is to identify the relationships between the tables. In this example there is a one-to-many relationship between members and their motorcycles: one member may have many motorcycles, but each motorcycle can only belong to one member.
When two tables have a one-to-many relationship, the relationship is created by placing values from the "one" table's key field into a field of the related records in the "many" table. When this is done, the key in the "one" table is known as a primary key and a foreign key in the "many" table.
The final result is a relational database model. When a database model satisfies all the technical requirements it is said to be rationalized.
The objective of rationalizing a database structure is to eliminate redundancy in order to save disk space and to simplify updates by insuring that every piece of information exists in only one place. The only fields that repeat are the foreign keys.