Databases Reference
In-Depth Information
We will translate the requirements into tables, columns, and relations. It will be the
single point of truth of our system. Because our whole system is built upon this model,
it's very important to spend suficient time on it. A data model is also a great means
to communicate with your customers and among developers about the system and
design of the database. When a database is well designed, it can be easily maintained
for future development.There are a number of
Computer Aided Software Engineering
(
CASE
) tools that you can use to create a data model. Besides data modeling, some
of these CASE tools can also be used to maintain all the PL/SQL packages, functions,
procedures, and trigger code that we use in our applications. Oracle itself provides
Oracle Designer and Data Modeler from SQL Developer. The following diagram shows
Data Modeler. One of the advantages of using such a tool is the ability to generate and
reverse engineer the database creation scripts in an intuitive graphical manner.
SQL Developer Data Modeler
Relations between the tables are always in a one-to-many relationship; for example,
a user can perform one or more searches. We can use colors to differentiate between
tables that have a lot of mutations and tables that don't have any. Those tables can be
candidates for creating lists of values (discussed later in this chapter).
