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Who is this for
This article is for those who would like to know more of the features of HTML::Mason
What you need to know
Perl programming, HTML::Mason basics
Introduction
In
the past 3 articles, we discussed about the different components of
HTML::Mason. Most web sites require database access so when you create
your HTML::Mason pages, you should also consider this.
Data base access in HTML::Mason
Accessing
database in HTML::Mason is similar to accessing it in an ordinary Perl
script. Let's say you have a database called article and you want to
list all the rows in the article table. Assuming that your database is
MySQL, you would do this in an ordinary Perl script:
use DBI;
my $db = DBI->connect('DBI:mysql:database=article',
'userid', 'password');
my $sql = qq { SELECT DATEPUBLISHED, TITLE FROM ARTICLE };
$sth = $db->prepare($sql);
$sht->execute();
so on |
In
HTML::Mason, you also need to connect to your database and issue SQL
statements. If you have only one page that will require database
access, you can hard code the connection statement. However, if you
have 10 pages that require database access, you can still hard code the
connection statement. But if you need to change the userid or password,
you will need to change them in all these pages.
A simpler way is to separate the connection script and call it, say, connect.html
<%perl>
use DBI;
return DBI->connect('DBI;mysql;database=article',
'userid', 'password'); |
Then you can call this component from all webpages that need database access:
<%init>
use DBI;
my $db = $m->comp('connect.html');
my $sql = qq { SELECT DATEPUBLISHED, TITLE FROM ARTICLE };
my $sth = $db->prepare($sql);
$sth->execute();
so on |
If you did it this
way, any changes to the database connection statement will not require
that you change all 100 scripts. Just go in and change the connect.html
statement and you are all set!
Displaying all Rows
Now that you have selected a set of rows, you need to display them:
To do this, you can display them in a table like this:
<HTML>
<HEAD>
</HEAD>
<body>
<TABLE BORDER=1>
<TR>
<th>Date</th><th>Title</th>
</TR>
% while (my $rec = $sth->fetchrow_hashref() ) {
<tr>
<td><% $rec->{DATEPUBLISHED} %></td>
<td>
<A HREF=view.html?date=<% $rec->{DATEPUBLISHED} %> >
<% $rec->{TITLE} %>
</A>
</td>
</tr>
% }
</TABLE>
</BODY>
</HTML> |
The result will look something like this: |
| Date | Time
| 2001-04-24
|
| 2001-05-24
|
| 2001-07-24
|
| 2001-08-24
|
|
|
