Chapter 10: Connecting to a Database: Advanced

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The purpose of this chapter is to continue the study of using a database with middleware programming by demonstrating deleting and updating records in the database, and complex queries involving more than one table.

Background

The previous chapter showed the benefits of middleware by demonstrating how to build a Web application giving visitors to a Web site the ability to add information to a database and to display the current database contents. This capability changes the Web from a static to a dynamic medium. However, this is only the start of what is possible.

The benefits of databases as opposed to simple files, also known as flat files, are demonstrated when the application requires operations other than the insertion of records and display of all records. This chapter will build on the prior ones and show you how to delete records, update information in records, and request customized views of the database contents.

The main thrust of this chapter is on the use of SQL. However, you also need to know how to generate the HTML to display information on the client computer and acquire input from the person sitting at the client computer. This will require new PHP and ASP/JavaScript coding techniques. The situation is a reminder of the general term for PHP and ASP: middleware. The PHP and ASP scripts operate in the middle: between the database management systems (DBMS) software on the server computer and the browser that interprets HTML on the client computer.