Starting Out
The first thing we need to do is verify that the two major components
of this tutorial are working correctly. If you do this now, it will rule
out a whole host of potential errors when you are attempting to debug
the minor scripts written in this tutorial.
2.1 "Hello World" in PHP
"Hello World" has got to be one of the most maligned programs
in the world. (Aside from various Microsoft's products.) It is exceedingly
simplistic to write and does little. What it does prove however is that
the basic workings of PHP are up and running.
Create a file called hello.php and type in the following:
<html>
<body>
<?
echo("Hello World\n");
?>
</body>
</html>
When you view that file on your web server, you should see a single
line saying: Hello World. If you do, then
PHP is working correctly working.
2.2 Creating a test table in MySQL
I'm assuming that you have telnet access to a machine which can
connect to the MySQL server. If you do not, it is still possible to
create and manipulate database on a remote server through Perl and the
DBI interface, however that is outside the bounds of this small
tutorial. If you're looking for a web interface to maintain or
administer MySQL, I recommend you take a look at phpMyAdmin
Connect to your MySQL database server and create a test database and
the test table that we'll use for this tutorial.
%> mysql -uUSERNAME -pPASSWORD
mysql> create database phptest;
Query OK, 1 row affected (0.13 sec)
mysql> use phptest;
Database changed
mysql> create table TEST
-> (
-> ID int auto_increment primary key,
-> Name varchar(32),
-> Age int,
-> Salary int
-> );
Query OK, 0 rows affected (0.11 sec)
Using varchar instead of char is
recommended unless you are going to restrict the length of the strings
entered by the user in HTML forms. The 32 in the table
definition sets the maximum size the string can be. Columns of type
varchar can be up to 255 characters long.
2.3 Adding information to the test table
Now we'll add a bunch of rows to the table so we'll have something to
play with when we try to access this database via PHP.
mysql> insert into TEST values (0,'Billy Bob Barker','87','93000');
Query OK, 1 row affected (0.09 sec)
mysql> insert into TEST values (0,'Sniffling Sam Sloth','23','12000');
Query OK, 1 row affected (0.01 sec)
mysql> insert into TEST values (0,'Roy Bartley','31','87000');
Query OK, 1 row affected (0.01 sec)
mysql> insert into TEST values (0,'Leroy Longrad','45','63000');
Query OK, 1 row affected (0.01 sec)
mysql> insert into TEST values (0,'Amy Antwerp','37','34000');
Query OK, 1 row affected (0.01 sec)
mysql> insert into TEST values (0,'Kim Kruger','57','76000');
Query OK, 1 row affected (0.01 sec)
The resulting table data should look like:
mysql> select * from TEST;
+----+---------------------+------+--------+
| ID | Name | Age | Salary |
+----+---------------------+------+--------+
| 1 | Billy Bob Barker | 87 | 93000 |
| 2 | Sniffling Sam Sloth | 23 | 12000 |
| 3 | Roy Bartley | 31 | 87000 |
| 4 | Leroy Longrad | 45 | 63000 |
| 5 | Amy Antwerp | 37 | 34000 |
| 6 | Kim Kruger | 57 | 76000 |
+----+---------------------+------+--------+
6 rows in set (0.16 sec)
2.4 Connecting to the database with PHP
Now that we know that PHP is working and there is information ready
and waiting in the database, it's time to tie them both together. Save
the PHP class code to a file called
"util.php" or something equally meaningful
in the directory where the rest of your PHP files will reside. Edit
this file and update the username and password which you will be using
to connect to the database.
Create a new file, "testdb.php" and type
in the following:
<html>
<body>
<?
require("util.php");
$sql = new MySQL_class;
$sql->Create("phptest");
echo("Database connection successful.\n");
?>
</body>
</html>
Loading this file into your browser, you should see
Database connection successful.
If you do, then you've contacted the database, logged in with the
right password and are ready to roll!
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