Free Programming Source Codes and Computer Programming Tutorials: Student Information System Using OOP in PHP and MySQL

The use of computers today is very important compared than before every transactions being performed is being done using a computer. If we are very observant enough when we to a super market and purchase some foods when we pay for the foods he have selected the cashier uses barcode scanner and a computer with a Point of Sale program installed on it. It makes the transaction more efficient , accurate and more faster because all the information for each item be purchase is being stored in database system that can be easily retrieve and performs a series of computation needed for that particular transaction. On the part of the supermarket the use of this can of application program Point of Sale for example is also beneficial because they can monitor the products that are saleable to the consumer and they can also perform inventory of their products more effectively this approach can save big amount of time, manpower and money to the part of the owner of the super market. It can also help them maximize losses because they can check each products they sold accurately compared to the use of manual cash register method that is prone for errors and time consuming also if they will conduct inventory of their stocks day to day.

In this article I will show you how to build a database application using PHP and MySQL but this time we will using object oriented approach in creating our database application we will using the mysqli connection in PHP and MySQL. When I started programming in PHP and MySQL way back in 2006 most of my work in database development is using the procedural approach of programming. I will start from the top to bottom until I finish writing the application. Using this approach I was able to creating a bunch of different database applications for different customers and clients that I have. However this approach is not good if you are working with other programmers that uses object oriented approach in programming why because your code is not easy to maintain and you can’t use code libraries that is written in object oriented approach. Basically if you ask me what are the benefits of using object oriented approach in programming basically in my own experience in Java application development the biggest advantage of OOP approach is code usability it means when we write or use the code written by other programmers it is very easy to use. Another advantage of using OOP as an approach in programming is that it is easier for us to modify and maintain the existing code that we have compared to its counterpart procedural programming. For your information object oriented programming started with the programming language called Simula a very popular programming language in Europe. To give you some idea working with object oriented programming we are dealing with objects. An object is the things that we can see in our environment it can be a thing, living things such as car, person, tools. Every object has an attribute which refers to the physical characteristic of the a particular object for an example a car the color of the car is red, it has size, weight this is called attributes. On the other hand methods are the actions that is being performed by an object for a car is can move forward, backward and stop it means the method is an action performed by the object that is the car for instance.

The program that I will represent in this article is Students Information System using Object Oriented Approach. Before that I would like to mention that some portion of the code that I use in my program is based on the work

of my Mr. Mike Dalisay in his article about CRUD application using PHP and MySQLi here is his website http://www.codeofaninja.com he is also a fellow Filipino software developer like me. You can visit his website to learn more about web programming. Student Information System is a application program that I wrote in order for the school to store and manage the records of their students enrolled on their different program in their school. The program will accept the first name, last name, course, birthday, year and section where the student belongs and the email address that can be used by the school to contact the student. I also include an SQL dumb file for easy creation of database, table and a copy of sample records. There are still many things that you can improve this program you can all print function and login to secure your application against intruders.

The first thing that we do is to create a database connection below is a the code that will performed such operation.

db_connect.php

<?php

$db_host = "localhost";

$db_username = "root";

$db_password = "";

$db_name = "info";

$mysqli = new mysqli($db_host, $db_username, $db_password, $db_name);

if(mysqli_connect_errno()) {

echo "Error: Could not connect to database.";

exit;

}

In this code we use already an object oriented approach in creating an object with this command $mysqli = new mysqli($db_host, $db_username, $db_password, $db_name); by using the keyword new we care creating a connection of mysqli. The term mysqli mean I means improved version of mysql_connect() function in mysql. The next portion of our code is the index.php in this portion we will fetch the records from our database info and the table students to be displayed in the screen as a list of records. The user in this portion of our code has the ability to update our records or delete our records from the database.

Index.php

<html>

<head>

<title>

Students Information System

</title>

body {

font-size : 1.5em;

font-family: Arial, Helvetica, sans-serif;

color : black;

background-image:url("sky.jpg");

}

</style>

<body>

<br>

<hr>

<h2 align="center"> Students Information System </h2>

</font>

<hr>

<?php

include 'db_connect.php';

$action = isset($_GET['action']) ? $_GET['action'] : "";

if($action=='delete'){

$sql = "DELETE FROM students WHERE id = ?";

if($stmt = $mysqli->prepare($sql)){

$stmt->bind_param("i", $_GET['id']);

if($stmt->execute()){

echo "<br> <center>";

echo "Record has been deleted. </center>";

$stmt->close();

}else{

die("Unable to delete.");

}

$query = "select * from students";

$result = $mysqli->query( $query );

$num_results = $result->num_rows;

if( $num_results ){

echo "<br><br>";

echo "<table border='2' align='center'>";

echo "<tr>";

echo "<th> <font color='red'> Firstname</th></font>";

echo "<th><font color='red'> Lastname</th</font>";

echo "<th><font color='red'> Course</th</font>";

echo "<th><font color='red'> Birthday</th></font>";

echo "<th><font color='red'>Year/Section</th></font>";

echo "<th><font color='red'>Email</th></font>";

echo "<th><font color='red'>Record Options</th> </font>";

echo "</tr>";

while( $row = $result->fetch_assoc() ){

extract($row);

echo "<tr>";

echo "<td> <center> {$firstname} </center></td>";

echo "<td> <center> {$lastname} </center></td>";

echo "<td> <center> {$course} </center></td>";

echo "<td> <center> {$bday} </center></td>";

echo "<td> <center>{$year_section} </center></td>";

echo "<td> <center>{$email} </center></td>";

echo "<td>";

echo "<a href='edit.php?id={$id}'>Update Record</a>";

echo " / ";

echo "<a href='#' onclick='delete_user( {$id} );'>Delete Record</a>";

echo "</td>";

echo "</tr>";

}

echo "</table>";

}

else{

echo "<br><br> <center>";

echo "No More Record(s) Found in the Database.";

echo "</center>";

}

echo "<p align='center'><br><br>";

echo "<a href='add.php' title='Click here to add a record in the database'>

ADD NEW RECORD</a> </p>";

$result->free();

$mysqli->close();

function delete_user( id ){

var answer = confirm('Are you sure?');

if ( answer ){

window.location = 'index.php?action=delete&id=' + id;

}

</script>

</body>

</html>

The third portion of our code is to add a record in our table students by the end user of our program. Kindly see the listing below there are some important comments to be read because you can understand how the mysqli works in our program.

add.php

<html>

<head>

<title>

Students Information System

</title>

body {

font-size : 1.5em;

font-family: Arial, Helvetica, sans-serif;

color : black;

background-image:url("sky.jpg");

}

</style>

<?php

error_reporting(0);

if($_POST){

include 'db_connect.php';

$sql = "INSERT INTO

students (firstname, lastname, course, bday,year_section,email)

VALUES

(?, ?, ?, ?, ?, ?)";

if($stmt = $mysqli->prepare($sql) ){

* Binding of the values,

* "sssssss" means 6 strings were being binded,

* aside from s for string, you can also use:

* i for integer

* d for decimal

* b for blob

$stmt->bind_param(

"ssssss",

$_POST['firstname'],

$_POST['lastname'],

$_POST['course'],

$_POST['bday'],

$_POST['year_section'],

$_POST['email']

);

if($stmt->execute()){

$message = "<br><br> <font color='red'> <center> Student Record has been save in the database. </center>";

$stmt->close();

}else{

die(" Sorry unable to save record in the database. Please contact your Programmer.");

}

}else{

die("Unable to prepare statement.");

}

$mysqli->close();

}

<br>

<h2> <center> ADD STUDENT RECORDS </center> </h2>

<hr>

<body>

<tr>

<td>Firstname</td>

</tr>

<tr>

<td>Lastname</td>

</tr>

<tr>

<td>Course</td>

</tr>

<tr>

<td>Birthday</td>

</tr>

<tr>

<td>Year and Section</td>

</tr>

<tr>

<td>Email</td>

</tr>

<td>

<a href='index.php' title="Click here to return to the main page">Return to Main Page</a>

</td>

</table>

<?php echo $message; ?>

</form>

</center>

</body>

</html>

One of the things that I have learned in writing this program your variable name that can be found in your ><input type='text' name='course' size="50" /> just like this one must be the same in terms of variable name declaration in your table which referring to your fields. If you are not following the rules you will be surprised to find out your code is not working properly. That is one of the things to be remembered in writing an object oriented approach in programming you must be precise all the time.

The last part of our code is the edit.php which performs changing of data values from our table. After the user make some changes he or she can return to the main page of our program to see the changes that has being made. Below is the complete program listing of our edit.php.

edit.php

<html>

<title>

College Students Information System

</title>

body {

font-size : 1.5em;

font-family: Arial, Helvetica, sans-serif;

color : black;

background-image:url("sky.jpg");

}

</style>

<body>

<?php

include 'db_connect.php';

if($_POST){

$sql = "UPDATE

students

SET

firstname = ?,

lastname = ?,

course = ?,

bday = ?,

year_section = ?,

email = ?

WHERE

id= ?";

$stmt = $mysqli->prepare($sql);

$stmt->bind_param(

'ssssssi',

$_POST['firstname'],

$_POST['lastname'],

$_POST['course'],

$_POST['bday'],

$_POST['year_section'],

$_POST['email'],

$_POST['id']

);

if($stmt->execute()){

echo "Student record is updated in the database ";

$stmt->close();

}else{

die("Sorry unable to update the record in the database");

}

$sql = "SELECT

id, firstname, lastname, course, bday, year_section, email

FROM

students

WHERE

id = \"" . $mysqli->real_escape_string($_GET['id']) . "\"

LIMIT

0,1";

$result = $mysqli->query( $sql );

$row = $result->fetch_assoc();

extract($row);

$result->free();

$mysqli->close();

<br>

<hr>

<h2> <center> UPDATE STUDENT RECORDS </center> </h2>

<hr>

<br>

</font>

<form action='edit.php?id=<?php echo $id; ?>' method='post' border='0'>

<tr>

<td>Firstname</td>

</tr>

<tr>

<td>Lastname</td>

</tr>

<tr>

<td>Course</td>

</tr>

<tr>

<td>Birthday</td>

</tr>

<tr>

<td>Year and Section</td>

</tr>

<tr>

<td>Email</td>

</tr>

<td>

<a href='index.php' title="Click here to return to the main page">Return to Main Page </a>

</td>

</tr>

</table>

</form>

</body>

</html>

This application program that I wrote is not very difficult is you know how to use object oriented approach in creating database application in PHP and MySQL using the mysqli connection approach. I hope you learn something out of it. If you have some comments, suggestions and questions about this article you can email me. I am very glad to answer your questions thank you very much for always supporting this website.

Happy Productive Programming Everyone.

If you have some questions please send me an email at jake.r.pomperada@gmail.com and jakerpomperada@yahoo.com. My mobile number here in the Philippines is 09173084360.