Introduction

When you store information in your database, you can easily retrieve it for use on the Web in a variety of ways. Query results can be displayed as unstructured paragraphs or as structured elements such as lists or tables; you can display static text or create hyperlinks. Query metadata can be useful when formatting query results, too, such as when generating an HTML table that displays a result set and uses its metadata to get the column headings for the table. These tasks combine query processing with web scripting, and are primarily a matter of properly encoding any special characters in the results (like & or <) and adding the appropriate HTML tags for the types of elements you want to produce.

This chapter shows how to generate several types of web output from query results. It also covers techniques for inserting binary data into your database and for retrieving and transferring that kind of information to clients. (It's easiest and most common to work with text for creating web pages from database content, but you can also use MySQL to help service requests for binary data such as images, sounds, or PDF files.)

The recipes here build on the techniques shown in Chapter 16 for generating web pages from scripts and for encoding output for display. See that chapter if you need some background in these topics.

The scripts from which the examples in this chapter are drawn can be found in the recipes distribution under the directories named for the servers used to run them. For Perl, PHP, and Python examples, look under the apache directory. For Java (JSP) examples, look under tomcat; you should already have installed these in the process of setting up the mcb application context (Recipe 16.4). The exception to this is that some of the utility routines used here are found in library files in the lib directory.

Note that not all languages are represented in every section. If a particular section seems to be "missing" an example for the language you're interested in, check the recipes distribution; it may contain the implementation you want, even if it's not shown here.