Web Database Applications with PHP, and MySQL

Case Study: Producing a select List

To conclude this chapter, we present a short case study of dynamically producing <form> components from a database. The techniques used are an application of the five-step querying process from Chapter 4.

We have already identified that the scripts in most of this chapter’s examples require that the user remember and reproduce the names of the wine regions. A far better approach—and one that works well for small numbers of items—is to present values using the HTML <select> input type. For the wine regions, the <select> input has the following structure:

<select name="regionName">
<option selected> All
<option> Barossa Valley
<option> Coonawarra
<option> Goulburn Valley
<option> Lower Hunter Valley
<option> Margaret River
<option> Riverland
<option> Rutherglen
<option> Swan Valley
<option> Upper Hunter Valley
</select>

With only a small number of wine regions, it is tempting to develop a static HTML page with an embedded list of region names. However, this is poor and inflexible. If the region database table changes—that is, new regions are added or deleted or you want to change a region_name value—you have to remember to update the HTML page. Moreover, a spelling mistake or an extra space when creating the HTML page renders a <select> option useless, because it no longer matches the values in the database when used for querying. A better approach is to use the techniques from Chapter 4 to dynamically query the database and produce a <select>