Programming PHP, 2nd Edition

PEAR DB Basics

Example 8-1 is a program to build an HTML table of information about science fiction books. It demonstrates how to use the PEAR DB library (which comes with PHP) to connect to a database, issue queries, check for errors, and transform the results of queries into HTML. Be sure to verify how to turn on PEAR with your setup of PHP, as the Unix/Linux flavor is slightly different to that of Windows. Go to http://www.pear.php.net/manual/en/installation.getting.php for a starting point on installation. The library is object-oriented, with a mixture of class methods (DB::connect( ), DB::iserror( )) and object methods ($db->query( ), $q->fetchInto( )).

Example 8-1. Display book information

<html><head><title>Library Books</title></head>
<body>

<table border=1>
<tr><th>Book</th><th>Year Published</th><th>Author</th></tr>
<?php
 // connect
 require_once('DB.php');
 $db = DB::connect("mysql://librarian:passw0rd@localhost/library");
 if (DB::iserror($db)) {
   die($db->getMessage(  ));
 }

 // issue the query
 $sql = "SELECT books.title,books.pub_year,authors.name
         FROM books, authors
         WHERE books.authorid=authors.authorid
         ORDER BY books.pub_year ASC";

 $q = $db->query($sql);
 if (DB::iserror($q)) {
   die($q->getMessage(  ));
 }

 // generate the table
 while ($q->fetchInto($row)) {
?>
<tr><td><?= $row[0] ?></td>
    <td><?= $row[1] ?></td>
    <td><?= $row[2] ?></td>
</tr>
<?php
 }
?>

The output of Example 8-1 is shown in Figure 8-1.

Figure 8-1. The Library page

Data Source Names

A data source name (DSN ) is ...