Dan Knight
- 2002.04.24
What is PHP? I can't summarize it any better than Try a New Language: PHP:
- PHP is an open-source, server-side, cross-platform scripting
language that is used to generate dynamic Web pages or to build
browser-based applications. The PHP script can be embedded in the HTML
page to generate HTML code that is inserted in the Web page at that
point, or the PHP script can generate the entire HTML output. One of
PHP's strengths is easy database integration.
That database integration usually comes from a MySQL database,
another open-source standard. For our purposes, creating a database
will be the first thing we do - before we even begin programming in
PHP. (And it's all free.)
Creating the Mac of the Day Database
The first piece of Low End Mac we be automated was the Mac of the
Day. I have a list of nearly 100 Apple models and clones, along with a
page link and a brief note on the model's significance. Here's what the
Mac Plus entry looks like in HTML:
- <A HREF="/1986/mac-plus/">Mac Plus</A>
(1/86-10/90). First Mac with SCSI, memory expansion. Longest model life
- over 4 years.
We could create a database containing that entire text string or
create one with separate fields for the link, the model name, and the
description. Neither system is inherently better than the other, but
using three fields will create a system where editing the description
could be done with no risk of messing up the link or the model name. It
will also have a second benefit, which I'll mention later.
MySQL has three types of string or text records. (Other record types
are numeric and time-related.) The CHAR type uses fixed length strings,
while VARCHAR allows variable string lengths. Although that's a more
efficient use of space, VARCHAR adds overhead and reduces performance.
Both of these field types are limited to 255 characters, which will be
plenty for our needs.
The third string record is BLOB or TEXT fields, which can be as
large as 65,535 characters. We might use such fields when we work with
mailing lists and articles, but we don't need such large fields right
now.
The longest model name is under 30 characters, and the longest link
is just over 20 characters, so we'll give ourselves a bit of room and
give the model name field a maximum length of 32 and the link a maximum
size of 24 characters.
A few of the descriptions are around 100 characters, so we'll set
the maximum size for that text field to 128 characters.
To create the database, you'll need to log into the MySQL server
you'll be using. Your ISP or system administrator should be able to
provide all the information you need to do that. If you're using
Telnet, type the following at the prompt to create your database:
mysql> create database macs;
This creates an empty database named "macs" - and it's just waiting
for us to create a table for our data. We'll be creating the following
fields:
mysql> CREATE TABLE mod (
-> id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
-> link CHAR(24),
-> model CHAR(32),
-> text CHAR(128),
-> );
The first line creates a table called "mod" (Mac of the Day") within
our database. The first field gives each record a unique and
automatically created ID number with a maximum value way up there in
the billions. PRIMARY KEY declares id as the primary field in
this table, meaning it is the one MySQL will index and access most
readily.
- NOTE: I didn't do it this way. My son Brian <http://brkn.net/> told me about a
program called
PHPMyAdmin that's much easier than using Telnet.
All that remains is to move the data from my current HTML file into
MySQL.
Filling the Mac of the Day Database
Call me lazy, but I simply don't want to spend a lot of time
rekeying this information or doing the cut-and-paste thing.
.
