This tutorial shows you how to use two open source, cross-platform tools for creating a
dynamic Web site: PHP and MySQL. When we are finished, you will know how
dynamic sites work and how they serve the content, and you will be ready to serve
your own dynamic content from your site.
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 2 http://codewalkers.com/tutorials/9/1.html
About this tutorial
This tutorial originally appeared at (http://www-106.ibm.com/developerworks) IBM
DeveloperWorks. It is reprinted here with the permission of the author.
Should I take this tutorial?
This tutorial shows you how to use two open source, cross-platform tools for creating a
dynamic Web site: PHP and MySQL. When we are finished, you will know how
dynamic sites work and how they serve the content, and you will be ready to serve
your own dynamic content from your site.
About the author
For technical questions about the content of this tutorial, contact the author, Md.
Ashraful Anam, at russell@bangla.net or at his website (http://www.anamtech.com)
http://www.anamtech.com
Md. Ashraful Anam works as an independent Web developer. Having conquered the
Windows platform, he recently changed his interest to Linux and immediately fell in
love with it.
In his spare time he can be seen wandering the virtual avenues of the net, testing open
source software, and trying to promote his country, Bangladesh, in the international IT
market. He can be reached at russell@bangla.net.
Introduction and installation
The need for dynamic content
The Web is no longer static; it's dynamic. As the information content of the Web grows,
so does the need to make Web sites more dynamic. Think of an e-shop that has 1,000
products. The owner has to create 1,000 Web pages (one for each product), and
whenever anything changes, the owner has to change all those pages. Ouch!!!
Wouldn't it be easier to have only one page that created and served the content on the
fly from the information about the products stored in a database, depending on the
client request?
Nowadays sites have to change constantly and provide up-to-date news, information,
stock prices, and customized pages. PHP and SQL are two ways to make your site
dynamic.
PHP PHP is a robust, server-side, open source scripting language that is extremely
flexible and actually fun to learn. PHP is also cross platform, which means your PHP
scripts will run on Unix, Linux, or an NT server.
MySQL SQL is the standard query language for interacting with databases. MySQL is
an open source, SQL database server that is more or less free and extremely fast.
MySQL is also cross platform.
Installing Apache server routines
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 3 http://codewalkers.com/tutorials/9/1.htmlFirst we will install the Apache server routines in the Linux environment. To install
these packages you will need root access to your server. If someone else is hosting
your site, ask the administrator to install them for you.
Installing Apache is relatively simple. First download the Apache archive, apache_ x. x.
xx. tar. gz (the latest I downloaded was apache_ 1.3.14. tar. gz) from the Apache site
and save it in /tmp/ src directory. Go to that directory:
# cd /tmp/src/
Extract the files with the command:
# gunzip -dc apache_x.x.xx.tar.gz | tar xv
replacing those xs with your version number. Change to the directory that has been
created:
# cd apache_x.x.xx
Now to configure and install apache, type the commands:
# ./ configure --prefix=/usr/local/apache --enable-module=so
# make
# make install
This will install Apache in the directory /usr/ local/ apache. If you want to install Apache
to a different directory, replace /usr/ local/ apache with your directory in the prefix.
That's it! Apache is installed.
You might want to change the default server name to something of real value. To do
this, open the httpd. conf file (located at /usr/ local/ apache/ conf) and find the line
starting with ServerName. Change it to ServerName localhost.
To test your install, start up your Apache HTTP server by running:
# /usr/local/apache/bin/apachectl start
You should see a message like "httpd started". Open your Web browser and type
"http://localhost/" in the location bar (replace localhost with your ServerName if you set
it differently). You should see a nice welcome page.
Installing MySQL
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 4 http://codewalkers.com/tutorials/9/1.htmlNext comes MySQL. We will follow the same procedure (replacing those xs again with
our version number). Download the source from the MySQL site and save it in /tmp/src.
The latest version I found was mysql-3.22.32.tar.gz.
# cd /tmp/src/
# gunzip -dc mysql-x.xx.xx.tar.gz | tar xv
# cd mysql-x.xx.xx
# ./ configure --prefix=/usr/local/mysql
# make
# make install
MySQL is installed. Now you need to create the grant tables:
# scripts/mysql_install_db
Then start the MySQL server:
# /usr/local/bin/safe_mysqld &
And test your installation by typing:
mysql -uroot -p
At the password prompt, just press Enter. You should see something like:
Welcome to MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5 to server version 3.22.34
Type 'help' for help.
mysql>
If you see this, you have MySQL running properly. If you don't, try installing MySQL
again. Type status to see the MySQL server status. Type quit to exit the prompt.
Installing PHP
We will follow a similar procedure to install PHP. Download and save the source from
the PHP site to /tmp/ src:
# cd /tmp/ src/
# gunzip -dc php-x.x.xx.tar.gz | tar xv
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 5 http://codewalkers.com/tutorials/9/1.html
# cd php-x.x.xx
# ./configure --with-mysql=/usr/local/mysql --with-apxs=/usr/local/apache/bin/apxs
# make
# make install
Copy the ini file to the proper directory:
# cp php.ini-dist /usr/local/lib/php.ini
Open httpd. conf in your text editor (probably located in /usr/local/apache/conf
directory), and find a section that looks like the following:
# And for PHP 4. x, use:
#
#AddType application/x-httpd-php .php
#AddType application/x-httpd-php-source .phps
Just remove those #s before the AddType line so that it looks like:
# And for PHP 4. x, use:
#
AddType application/x-httpd-php .php .phtml
AddType application/x-httpd-php-source .phps
Save your file and restart apache:
# /usr/local/apache/bin/apachectl stop
# /usr/local/apache/bin/apachectl start
Then test whether you have PHP installed properly. Type the following code in a text
editor and save it as test. php in a directory accessible by your Web server:
phpinfo();
?>
Set the permission of the file to executable by typing at console chmod 775 test. php,
and then view it with your browser. You should see a detailed description of the
environment variables in PHP similar to the image below. If you don't, then PHP was
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 6 http://codewalkers.com/tutorials/9/1.html
not installed properly. Try reinstalling it. Make sure there is a section "MySQL" in the
php info; if not, MySQL connectivity will not work.
Your first script
Following tradition, we will begin coding with a "hello world" example. Fire up your text
editor and type the following code:
echo "Hello World";
?>
Save the file as first.php and view it in the browser (remember to set the permission to
chmod 775 first). The page shows "Hello World". View the HTML source of this page
through your browser. You will only see the text Hello World. This happened because
PHP processed the code, and the code told PHP to output the string "Hello World".
Notice the . These are delimiters and enclose a block of PHP code.
tells PHP to
stop processing. All lines beyond this scope are passed as HTML to the browser.
Your first database
Now that we have PHP running properly and have created our first script, let's create
our first database and see what we can do with it. Drop to console and type in the
following command:
mysqladmin -uroot create learndb
This creates a database named "learndb" for us to use. Here we have assumed that
you are root user. If you are logged in as another user, just use the command
mysqladmin -uusername -pyourpassword create learndb, replacing username and
yourpassword with your username and password respectively. If you are hosting your
site through a hosting company, you probably don't have permission to run
mysqladmin. In this case, you have to ask your server administrator to create the
database for you.
Next we will create tables in this database and enter some information. Go to the
console. Type:
mysql
You should see something like:
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 7 http://codewalkers.com/tutorials/9/1.html
Welcome to MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5 to server version 3.22.34
Type 'help' for help.
Type:
CONNECT learndb
CREATE TABLE personnel
(
id int NOT NULL AUTO_INCREMENT,
firstname varchar(25),
lastname varchar(20),
nick varchar(12),
email varchar(35),
salary int,
PRIMARY KEY (id),
UNIQUE id (id)
);
INSERT INTO personnel VALUES ('1', 'John', 'Lever', 'John',
'john@everywhere.net', '75000');
INSERT INTO personnel VALUES ('2', 'Camilla', 'Anderson', 'Rose',
'rose@flower.com', '66000');
This creates a table with 5 fields and puts some information in it.
Where's my view?
Now that we have a database with some information with it, let's see if we can view it
with PHP. Save the following text as viewdb. php:
$db = mysql_connect("localhost", "root", "");
mysql_select_db("learndb",$db);
$result = mysql_query("SELECT * FROM personnel",$db);
echo "
| Full Name | Nick
Name | Salary |
| ";
echo $myrow["firstname"]; echo " "; echo $myrow["lastname"]; echo " | ";
echo $myrow["nick"]; echo " | ";
echo $myrow["salary"]; Create dynamic sites with PHP & MySQL by Md. Ashraful Anam Page 8 http://codewalkers.com/tutorials/9/1.html } echo " |
?>
Run it through your browser and you will see a personnel database. But what is this
code doing and how is it generated? Let's examine the code. First we declare a
variable $db. In PHP we declare a variable by putting the '$ ' sign before it. The string
after $ is the name of that variable. We assign value to it by coding:
$variable_name= somevalue;
(example: $count= 4;)
Remember to put ';' after all the lines that are executable in PHP. So we declare the
variable $db and create a connection to the mysql database with the statement
"mysql_connect("localhost", "root", "")". In plain English, it means connect to MySQL
database in localhost server with the username root and password "". Replace them
with your own username and password if they are different.
Then we assign a pointer to this database to $db; in other words, $db points to our
database server localhost. Next we select the database with which we want to interact
with the lines "mysql_select_db("learndb",$db);" which means we wish to use the
database "learndb" located by the pointer variable $db. But we want information from
the database, so we query the database with the lines "$result =
mysql_query("SELECT * FROM personnel",$db);" The part "SELECT * FROM
personnel" is an SQL statement (in case you don't know SQL), which means select all
the stuff from the database personnel.
We run this query with the PHP command mysql_ query() and save the result returned
by the database to the variable $result. Now we can access the different data in the
different rows of the database from the $result variable. We use the function
mysql_fetch_array() to extract each row from $result and assign them to variable
$myrow. So $myrow contains information about each row as opposed to all the rows in
$result.
Then we output the data contained in each row. "echo $myrow["firstname"];" means
send to output the value contained in the field "firstname" of the row contained in
$myrow; in other words, we access different fields of the row with $myrow["fieldname"].
We have used the while() loop here, which means as long as or while there are data to
be extracted from $result, execute the lines within those brackets {}. Thus we get nicely
formatted output in our browser. Viewing the PHP code and the HTML source from the
browser side-by-side may help you easily understand the procedure. Congratulations!
You have created your first dynamic page.
Creating an HTML form
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 9 http://codewalkers.com/tutorials/9/1.htmlSo now you can view records stored in your MySQL database and display them in your
browser using PHP. But you want to add new record. Assuming that you know about
HTML forms, let's code a page that will do just that. First we'll create a static form,
datain.html:
Now we have a form that will post the information to a page "datain.php". We must
code this page so that it is able to process the posted data and send it to our MySQL
database. The following listing of datain.php will do that:
$db = mysql_connect("localhost", "root","");
mysql_select_db("learndb",$db);
$sql = "INSERT INTO personnel (firstname, lastname, nick, email,
salary) VALUES ('$first', '$last', '$nickname','$email','$salary')";
$result = mysql_query($sql);
echo "Thank you! Information entered.\ n";
?>
The first 3 lines are same as before, only we use the SQL command "INSERT INTO",
which means insert into the database into the columns specified (here firstname,
lastname, nick, email) the data contained in the variable '$first', '$last', '$nickname',
'$email' respectively.
But where did these variables come from? Well, PHP has a wonderful way of creating
the variables automatically from the data posted to it. So the text box with name "first"
created the variable $first and it contained the text typed in that textbox.
Important Note: As of PHP 4.2, php no longer automatically creates the variables for
you. If you want posted variables to be automatically created. You have to edit your
php.ini file and set the register_globals variable to on. The line should read:
register_globals = on
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 10 http://codewalkers.com/tutorials/9/1.html
If that is not possible, you have to initialize the variables in your code everytime. The
method is, if you are posting a form with the field "name" you have to write the
following code in the page where you are posting:
$name=$_POST[name];//for post method
$name=$_GET[name];//for get method
?>
The general format is:
$variablename=$_POST[the_field_posted_by_form];
?>
So the above code will look like:
$db = mysql_connect("localhost", "root","");
mysql_select_db("learndb",$db);
//for new PHP
$first=$_POST[first];
$last=$_POST[last];
$nickname=$_POST[nickname];
$email=$_POST[email];
$salary=$_POST[salary];
//
$sql = "INSERT INTO personnel (firstname, lastname, nick, email,
salary)
VALUES ('$first','$last','$nickname','$email','$salary')";
$result = mysql_query($sql);
echo "Thank you! Information entered.\n";
?>
Putting it together
Now let's merge the code into one file. We will call it input.php
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 11 http://codewalkers.com/tutorials/9/1.html
if($submit)
{
$db = mysql_connect("localhost", "root","");
mysql_select_db("learndb",$db);
$sql = "INSERT INTO personnel (firstname, lastname, nick, email, salary) VALUES
('$first', '$last', '$nickname','$email','$salary')";
$result = mysql_query($sql);
echo "Thank you! Information entered.\n";
}
else
{
?>
}
?>
This creates a script that shows the form when there is no input or otherwise enters the
information into the database. How does the script understand when to do what? We
have already learned that PHP automatically creates variable with information posted
to it. So it will create the variable $submit if the form is posted. The script determines
whether there exists the variable $submit. If it exists and contains a value then we have
to enter the posted values into the database; otherwise, we have to show the form.
So now we can enter information to our database and view it. Try inserting some new
data into the database and check to see if it really works by viewing them with
viewdb.php.
Passing variables
Let's take a different view now and consider how information can be passed to another
PHP page. One method is by using forms as we have done already; another is by
using query strings. What are query strings? Change the line method="post" to
method="get" in our script input. php. Now try submitting new data into the database
with it. After clicking submit you will see our familiar "Thank you! Information entered" in
the browser. But look at the URL. It looks something like:
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 12 http://codewalkers.com/tutorials/9/1.html
Look closely. Now the information is passed as a string in the URL instead of posting
directly. The sentence after the ? is the query string, and as you can see it contains the
name of the variable and its values. When PHP receives a query string like ?first=John
it automatically creates a variable named $first and assigns the value from the query
string to it. So it is equivalent to $first="John"; When more than one variable is present,
the variables are separated by an ampersand (&).
If you don't have the register_globals=on option enabled, be sure to initialize the
variables with $_GET like $first=$_GET[first];
Viewing individual rows
So now we will create a script that will display the information of a particular row in our
database defined by the variable $id. Save the following code as view.php. Try viewing
it through your Web server as http://yourhost/view.php?id=2 (here we have passed the
variable $id=2 through the query string). The page should show information
corresponding to the id 2 in the MySQL database.
$db = mysql_connect("localhost", "root", "");
mysql_select_db("learndb",$db);
$result = mysql_query("SELECT * FROM personnel WHERE id=$id",$db);
$myrow = mysql_fetch_array($result);
echo "First Name: ".$myrow["firstname"];
echo "
Last Name: ".$myrow["lastname"];
echo "
Nick Name: ".$myrow["nick"];
echo "
Email address: ".$myrow["email"];
echo "
Salary: ".$myrow["salary"];
?>
Here the SQL command has changed and it tells the database to search for the row
that has the value $id. But can't multiple rows contain the same values of id? Generally
a column can contain any value, the same or different. But in our database two rows
can never have the same value of id, as we have defined id as UNIQUE when we
created our database.
We immediately modify our previous viewdb.php to viewdb2.php so that it can call
view.php with the proper query string.
$db = mysql_connect("localhost", "root", "");
mysql_select_db("learndb",$db);
$result = mysql_ query("SELECT * FROM personnel",$db);
echo "
| Full Name | Nick
Name | Options |
| ".$myrow["firstname"]." ".$myrow["lastname"]." | ".$myrow["nick"];
echo " | View";
} echo " |
?>
Viewing this page will show a list of names and corresponding nicknames. Look at the
third column with a hyperlink view. Take your mouse over the hyperlink and look what it
points to. The link should be something like http://yourhost/view.php?id=3 and the links
in each row will be different. Click on one of the links. It will bring up our previously
coded view. php showing the detailed information of that person. How is this achieved?
Let's take a look at our code viewdb2.php. Look at line 11, where all the real stuff takes
place. The only unfamiliar thing here should be those odd dots (.) all around the line.
The dot (.) is a concatenating operator in PHP, which means it concatenates the two
strings on its two sides, which in turn means that if we write echo "Hello"."World", the
output will actually be "HelloWorld". In our example we use the concatenate operator to
generate a line like:
for the browser.
Deleting rows
So far we have only entered new information in our database and viewed it. Where's
the fun if we can't trash some of those data, at least the useless ones? Our delete.php
will do just that. It works exactly like view.php. The only difference is the SQL
command "DELETE FROM personnel WHERE id=$id", which tell MySQL to delete the
row that contains the id corresponding to the variable $id. Generally, the SQL
command for deleting a row is DELETE FROM database_name WHERE
field_name=somevalue
$db = mysql_connect("localhost", "root", "");
mysql_select_db("learndb",$db);
mysql_query("DELETE FROM personnel WHERE id=$id",$db);
echo "Information Deleted";
?>
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 14 http://codewalkers.com/tutorials/9/1.html
Once again we modify our previous viewdb2.php script to viewdb3.php to add this new
feature. The additions should be obvious.
$db = mysql_connect("localhost", "root", "");
mysql_select_db("learndb",$db);
$result = mysql_query("SELECT * FROM personnel",$db);
echo "
| Full Name | Nick
Name | Options |
| ".$myrow["firstname"]." ".$myrow["nick"];
echo " | View ";
echo "Delete"; } echo " |
?>
Try clicking on delete and then view the database again with viewdb3.php to verify that
the row was really deleted. You may have to refresh your browser.
Editing data
So far we have viewed and deleted database content. But sometimes we need to edit
database content. For this we will modify our previously coded input.php file. By now
you are familiar with the concept of passing variables by URL. We will call this modified
script addedit.php:
if($submit)
{
$db = mysql_connect("localhost", "root","");
mysql_select_db("learndb",$db);
$sql = "INSERT INTO personnel (firstname, lastname, nick, email,
salary)
VALUES ('$first','$last','$nickname','$email','$salary')";
$result = mysql_query($sql);
echo "Thank you! Information entered.\n";
}
else if($update)
{
$db = mysql_connect("localhost", "root","");
mysql_select_db("learndb",$db);
$sql = "UPDATE personnel SET firstname='$first',
lastname='$last', nick='$nickname', email='$email', salary='$salary'
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 15 http://codewalkers.com/tutorials/9/1.html
WHERE id=$id";
$result = mysql_query($sql);
echo "Thank you! Information updated.\n";
}
else if($id)
{
$db = mysql_connect("localhost", "root", "");
mysql_select_db("learndb",$db);
$result = mysql_query("SELECT * FROM personnel WHERE id=$id",$db);
$myrow = mysql_fetch_array($result);
?>
}
else
{
?>
}
?>
Hmmm... the code looks quite complex. But really it isn't. Previously input. php had two
features: it could add information to the database or could show the form. We'll add two
more features to it: the ability to show the same form but with values of a particular
person already there and the ability to update records for that person. The SQL
commands for entering new information and updating existing information are different,
so we can't use our previous code for entering information.
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 16 http://codewalkers.com/tutorials/9/1.html
The script searches for the $submit variable. If it contains some value, then someone
submitted new data and the information is entered into the database. If $submit does
not contain any value, then someone might have just posted their updated information,
so we check $update. If it contains a value, then we update that person's record with
the SQL statement "UPDATE personnel SET fieldname1= '$variablename1',
fieldname2= '$variablename2' ......... WHERE id=$id";". Otherwise, if someone provided
the id in the query string, we show that person's information, but this time in a form so
he may change it. If all these are not the case, we simply have to show the old form.
Experiment with the script. Open it with your browser to see what comes up. Then call
it providing query string ?id=1. Change the information and click update. Verify whether
the database is updated by viewing the database with viewdb3.php.
Another new element was just introduced. It is the global PHP variable $PHP_SELF.
This variable always contains the name of the script it is in and its location. We have
used this variable in a 'form action' so no matter what you name this file, this script will
always post information to itself.
Once again we modify our viewing script incorporating this feature. Here's the listing for
viewdb4.php:
$db = mysql_connect("localhost", "root", "");
mysql_ select_db("learndb",db);
$result = mysql_query("SELECT * FROM personnel",$db);
echo "
| Full Name | Nick
Name | Options |
| ".$myrow["firstname"]."
".$myrow["lastname"]." | ".$myrow["nick"];
echo " | View ";
echo "Delete "; echo "Edit"; } echo " |
?>
Searching our data
Information is useless if you can't find the data you require from a wealth of
information. We need a way to search our database, so let's implement a search
function. The page will show a static form initially and will show the search result when
we have something submitted.
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 17 http://codewalkers.com/tutorials/9/1.html
if ($searchstring)
{
$sql="SELECT * FROM personnel WHERE $searchtype LIKE '%$searchstring%'
ORDER BY firstname ASC";
$db = mysql_connect("localhost", "root", "");
mysql_select_db("learndb",$db);
$result = mysql_query($sql,$db);
echo "
| Full Name | Nick
Name | Options |
| ".$myrow["firstname"]."
".$myrow["lastname"]." | ".$myrow["nick"];
echo " | View";
} echo " |
}
else
{
?>
}
?>
The script checks whether a search string exists. If $searchstring contains a value,
then we have something to search; otherwise, we just show an HTML form. The part of
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 18 http://codewalkers.com/tutorials/9/1.html
code that searches is similar to our viewdb2.php. The SQL command deserves a bit of
explanation here. Let's look at it closely. The SQL command is:
"SELECT * FROM personnel WHERE $searchtype LIKE '%$searchstring%'
ORDER BY firstname ASC"
Two news things are introduced here, "LIKE" and "ORDER BY". LIKE simply means
'sounds like'. The '%' sign represents any possible combination of characters (numbers
or letters). So to find people whose first name starts with 'J' we would use the SQL
command:
"SELECT * FROM personnel WHERE firstname LIKE 'J%'"
To find those people with a name ending with J we have to use '%J'. If we wish find
people with 'J' anywhere in their name (first, middle, or last) we have to use '%J%'.
'ORDER BY' simply orders the records in ascending or descending order. The syntax
is:
"ORDER BY fieldname order_ method" where order_ method is ASC or DESC allowing
the ordering to be done in ASCending or DESCending order.
Tips for common tasks
We have covered the basics. Where you go from here is up to you. You know enough
now to implement some of these useful tasks:
* User database
You could implement a user database. You can add a login feature to this.
* News
You could code a section that always displays the latest news or maybe a "What's
new" section that's automatically generated. The TABLE could be something like:
CREATE TABLE news
(
id INT NOT NULL AUTO_ INCREMENT,
title VARCHAR(40),
newsbody TEXT,
news_ date DATE,
PRIMARY KEY (id),
UNIQUE id (id)
);
And assuming you want to automatically show the title of the latest five news items, the
code could be something like:
Create dynamic sites with PHP & MySQL
by Md. Ashraful Anam
Page 19 http://codewalkers.com/tutorials/9/1.html
$sql="SELECT * FROM news ORDER by news_date DESC";
$db = mysql_connect("localhost", "root", "");
mysql_select_db("newsdb",$db);
$result = mysql_query($sql,$db);
echo "Latest News:
";
$i=1;
while ($myrow = mysql_fetch_array($result))
{
echo "".$myrow["title"]."
";
$i=$i+1;
if($i>5)
break;
}
?>
* Product database
You could create a detailed database of your products. Clients could see all the
products or search for particular product.
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