At this stage, you can convert the business model of the car web portal presented in Chapter 1, Relational Databases, into a logical model. To help the developer to create a table, follow this minimal checklist:
- What is the primary key?
- What is the default value for each column?
- What is the type of each column?
- What are the constraints on each column or set of columns?
- Are permissions set correctly on tables, sequences, and schemas?
- Are foreign keys specified with the proper actions?
- What is the data life cycle?
- What are the operations allowed on the data?
To create the car web portal schema, the formal relational model won't be applied strictly. Also, surrogate keys will be used instead of natural keys. The advantages of using surrogate keys are as follows:
- Natural keys can change; you can change the current email address to another one. On...