Web Design

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A

database, in the simplest terms, is a structured collection of information, or records. Computer

databases can be used to store massive amounts of information in a format that makes it easy to

sort and find specific data points. Early databases were first developed in the years following World

War II. In the 1970s, a new model was proposed that more efficient data storage would be possible

if databases were created as a series of related tables. Today, almost every major database system on

the market follows this relational database model.

Understanding Relational Databases

Database Management Systems

A computer program that stores data is technically called a Database

Management System, or DBMS. Many hundreds of DBMS systems are available

today, and Web developers mostly rely on one of three systems for their work:

Microsoft SQL Server, MySQL, and Oracle. Each has advantages and

disadvantages. Due to its close relationship with PHP and its inclusion in the

WAMP and MAMP installers, this book looks at MySQL.

PHP and MySQL

Although PHP can use a technology called ODBC, or Open Database

Connectivity, to connect to Microsoft SQL Server, Microsoft Access, or

Oracle, it includes the ability to directly connect to a MySQL database.

This has the advantage of removing much of the abstraction and

additional overhead required when using ODBC, but it also means that

PHP applications must be written with a specific database in mind.

Relational Databases

A relational database is one that stores its information in a collection of tables. Each table stores data

about one specific topic. For example, in a database with product ordering information, the details about

the products would be in a table, and the details about the customers would be kept separate in a different

table. The database can then store information about the relationships between the data, so it would know

which customer ordered which product.