Applications often need to access databases to store and retrieve various kinds of data. A database (http://en.wikipedia.org/wiki/Database) is an organized collection of data. Although there are many kinds of databases (e.g., hierarchical, object oriented, and relational), relational databases, which organize data into tables that can be related to each other, are common.
Note In a relational database, each row stores a single item (e.g., an employee) and each column stores a single item attribute (e.g., an employee’s name).
Except for the most trivial of databases (e.g., Chapter 11’s flat file database based on a single data file), databases are created and managed through a database management system (DBMS) ...