In this article, we are going to join two tables using PHP and display them on the web page.
Introduction :
PHP is a server-side scripting language, which is used to connect with databases. Using this, we can get data from the database using PHP scripts. The database language that can be used to communicate with PHP is MySQL. MySQL is a database query language that is used to manage databases.
Requirements :
Xampp server - xampp server is used to store our database locally. We are going to access the data from xampp server using PHP.
In this article, we are taking the student details database that contains two tables. They are student_address and student_marks.
Structure of tables :
table1=student_address
table2=student_marks.
We are going to perform INNER JOIN, LEFT JOIN, RIGHT JOIN on these two tables.
1. INNER JOIN :
The INNER JOIN is a keyword that selects records that have matching values in both tables.
Syntax :
SELECT column 1,column 2,...column n
FROM table1
INNER JOIN table2
ON table1.column_name = table2.column_name;
Example :
Let student_address contains these details
And student_marks table includes
By using sid, we can join these two tables using an Inner join, since, sid is common in two tables.
- Query to display student_address details based on inner join -
SELECT * from student_address INNER JOIN student_marks on student_address.sid=student_marks.sid;
Result :
STUDENT-ID : 1 ----- NAME : sravan kumar ----- ADDRESS : kakumanu
STUDENT-ID : 2 ----- NAME : bobby ----- ADDRESS : kakumanu
STUDENT-ID : 3 ----- NAME : ojaswi ----- ADDRESS : hyderabad
STUDENT-ID : 4 ----- NAME : rohith ----- ADDRESS : hyderabad
- Query to display student_marks details based on inner join.
SELECT * from student_marks INNER JOIN student_address on student_address.sid=student_marks.sid
Result :
STUDENT-ID : 1 ----- SUBJECT 1 : 98 ----- SUBJECT 2 : 99
STUDENT-ID : 2 ----- SUBJECT 1 : 78 ----- SUBJECT 2 : 89
STUDENT-ID : 3 ----- SUBJECT 1 : 78 ----- SUBJECT 2 : 98
STUDENT-ID : 4 ----- SUBJECT 1 : 89 ----- SUBJECT 2 : 98
2. LEFT JOIN :
The LEFT JOIN keyword is used to return all records from the left table (table1), and the matching records from the right table (table2).
Syntax :
SELECT column1,column2,...columnn
FROM table1
LEFT JOIN table2
ON table1.column_name = table2.column_name;
- Query to display all student_address table based on student id using left join
SELECT * from student_address LEFT JOIN student_marks on student_address.sid=student_marks.sid
Result :
STUDENT-ID : 1 ----- NAME : sravan kumar ----- ADDRESS : kakumanu
STUDENT-ID : 2 ----- NAME : bobby ----- ADDRESS : kakumanu
STUDENT-ID : 3 ----- NAME : ojaswi ----- ADDRESS : hyderabad
STUDENT-ID : 4 ----- NAME : rohith ----- ADDRESS : hyderabad
STUDENT-ID : ----- NAME : gnanesh ----- ADDRESS : hyderabad
- Query to display all student_marks table based on student id using left join
SELECT * from student_marks LEFT JOIN student_address on student_address.sid=student_marks.sid
Result :
STUDENT-ID : 1 ----- SUBJECT 1 : 98 ----- SUBJECT 2 : 99
STUDENT-ID : 2 ----- SUBJECT 1 : 78 ----- SUBJECT 2 : 89
STUDENT-ID : 3 ----- SUBJECT 1 : 78 ----- SUBJECT 2 : 98
STUDENT-ID : 4 ----- SUBJECT 1 : 89 ----- SUBJECT 2 : 98
STUDENT-ID : ----- SUBJECT 1 : 89 ----- SUBJECT 2 : 79
3. RIGHT JOIN :
The RIGHT JOIN keyword is used to return all records from the right table (table2), and the matching records from the left table (table1).
Syntax :
SELECT column1,column2,...columnn
FROM table1
RIGHT JOIN table2
ON table1.column_name = table2.column_name;
- Query to display all student_address table based on student id using right join
SELECT * from student_address RIGHT JOIN student_marks on student_address.sid=student_marks.sid
Result :
STUDENT-ID : 1 ----- NAME : sravan kumar ----- ADDRESS : kakumanu
STUDENT-ID : 2 ----- NAME : bobby ----- ADDRESS : kakumanu
STUDENT-ID : 3 ----- NAME : ojaswi ----- ADDRESS : hyderabad
STUDENT-ID : 4 ----- NAME : rohith ----- ADDRESS : hyderabad
STUDENT-ID : 7 ----- NAME : ----- ADDRESS :
- Query to display all student_marks table based on student id using right join
SELECT * from student_marks RIGHT JOIN student_address on student_address.sid=student_marks.sid
Result :
STUDENT-ID : 1 ----- SUBJECT 1 : 98 ----- SUBJECT 2 : 99
STUDENT-ID : 2 ----- SUBJECT 1 : 78 ----- SUBJECT 2 : 89
STUDENT-ID : 3 ----- SUBJECT 1 : 78 ----- SUBJECT 2 : 98
STUDENT-ID : 4 ----- SUBJECT 1 : 89 ----- SUBJECT 2 : 98
STUDENT-ID : 5 ----- SUBJECT 1 : ----- SUBJECT 2 :
Approach :
- Create a database named database and create tables(student_address and student_marks)
- Insert records into two tables using PHP
- Write SQL query to perform all joins using PHP
- Observe the results.
Steps:
- Type "localhost/phpmyadmin" in your browser and create a database named "database" then create two tables named student_address and student_marks
Student_address table structure :
Student_marks table structure :
- Insert the records into the student_address table using PHP (data1.php) Run code by typing "localhost/data1.php"
PHP
<?php
//servername
$servername = "localhost";
//username
$username = "root";
//empty password
$password = "";
//database is the database name
$dbname = "database";
// Create connection by passing these connection parameters
$conn = new mysqli($servername, $username, $password, $dbname);
// Check this connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
//insert records into table
$sql = "INSERT INTO student_address VALUES (1,'sravan kumar','kakumanu');";
$sql .= "INSERT INTO student_address VALUES (2,'bobby','kakumanu');";
$sql .= "INSERT INTO student_address VALUES (3,'ojaswi','hyderabad');";
$sql .= "INSERT INTO student_address VALUES (4,'rohith','hyderabad');";
$sql .= "INSERT INTO student_address VALUES (5,'gnanesh','hyderabad');";
if ($conn->multi_query($sql) === TRUE) {
echo "data stored successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>
Output :
Write PHP code to insert details in the student_marks table. (data2.PHP)
PHP
<?php
//servername
$servername = "localhost";
//username
$username = "root";
//empty password
$password = "";
//database is the database name
$dbname = "database";
// Create connection by passing these connection parameters
$conn = new mysqli($servername, $username, $password, $dbname);
// Check this connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
//insert records into table
$sql = "INSERT INTO student_marks VALUES (1,98,99);";
$sql .= "INSERT INTO student_marks VALUES (2,78,89);";
$sql .= "INSERT INTO student_marks VALUES (3,78,98);";
$sql .= "INSERT INTO student_marks VALUES (4,89,98);";
$sql .= "INSERT INTO student_marks VALUES (7,89,79);";
if ($conn->multi_query($sql) === TRUE) {
echo "data stored successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>
Output :
Type "localhost/data2.php" to see the output
Write PHP code to perform inner join (form.php)
PHP
<html>
<body>
<?php
//servername
$servername = "localhost";
//username
$username = "root";
//empty password
$password = "";
//database is the database name
$dbname = "database";
// Create connection by passing these connection parameters
$conn = new mysqli($servername, $username, $password, $dbname);
echo "inner join on student_address: ";
echo "<br>";
echo "<br>";
//sql query to display all student_address table based on student id using inner join
$sql = "SELECT * from student_address INNER JOIN student_marks on student_address.sid=student_marks.sid";
$result = $conn->query($sql);
//display data on web page
while($row = mysqli_fetch_array($result)){
echo " STUDENT-ID : ". $row['sid'], " ----- NAME : ". $row['sname'] ," ----- ADDRESS : ". $row['saddress'] ;
echo "<br>";
}
echo "<br>";
echo "inner join on student_marks: ";
echo "<br>";
echo "<br>";
//sql query to display all student_marks table based on student id using inner join
$sql1 = "SELECT * from student_marks INNER JOIN student_address on student_address.sid=student_marks.sid";
$result1 = $conn->query($sql1);
//display data on web page
while($row = mysqli_fetch_array($result1)){
echo " STUDENT-ID : ". $row['sid'], " ----- SUBJECT 1 : ". $row['subject1'] ," ----- SUBJECT 2 : ". $row['subject2'] ;
echo "<br>";
}
//close the connection
$conn->close();
?>
</body>
</html>
Output :
Type "localhost/form.php" in your browser.
Write code to perform right join (form1.php)
PHP
<html>
<body>
<?php
//servername
$servername = "localhost";
//username
$username = "root";
//empty password
$password = "";
//database is the database name
$dbname = "database";
// Create connection by passing these connection parameters
$conn = new mysqli($servername, $username, $password, $dbname);
echo "right join on student_address: ";
echo "<br>";
echo "<br>";
//sql query to display all student_address table based on student id using right join
$sql = "SELECT * from student_address RIGHT JOIN student_marks on student_address.sid=student_marks.sid";
$result = $conn->query($sql);
//display data on web page
while($row = mysqli_fetch_array($result)){
echo " STUDENT-ID : ". $row['sid'], " ----- NAME : ". $row['sname'] ," ----- ADDRESS : ". $row['saddress'] ;
echo "<br>";
}
echo "<br>";
echo "right join on student_marks: ";
echo "<br>";
echo "<br>";
//sql query to display all student_marks table based on student id using right join
$sql1 = "SELECT * from student_marks RIGHT JOIN student_address on student_address.sid=student_marks.sid";
$result1 = $conn->query($sql1);
//display data on web page
while($row = mysqli_fetch_array($result1)){
echo " STUDENT-ID : ". $row['sid'], " ----- SUBJECT 1 : ". $row['subject1'] ," ----- SUBJECT 2 : ". $row['subject2'] ;
echo "<br>";
}
//close the connection
$conn->close();
?>
</body>
</html>
Output :
Type "localhost/form1.php" in your browser.
Write PHP code to perform left join (form2.php)
PHP
<html>
<body>
<?php
//servername
$servername = "localhost";
//username
$username = "root";
//empty password
$password = "";
//database is the database name
$dbname = "database";
// Create connection by passing these connection parameters
$conn = new mysqli($servername, $username, $password, $dbname);
echo "left join on student_address: ";
echo "<br>";
echo "<br>";
//sql query to display all student_address table based on student id using left join
$sql = "SELECT * from student_address LEFT JOIN student_marks on student_address.sid=student_marks.sid";
$result = $conn->query($sql);
//display data on web page
while($row = mysqli_fetch_array($result)){
echo " STUDENT-ID : ". $row['sid'], " ----- NAME : ". $row['sname'] ," ----- ADDRESS : ". $row['saddress'] ;
echo "<br>";
}
echo "<br>";
echo "left join on student_marks: ";
echo "<br>";
echo "<br>";
//sql query to display all student_marks table based on student id using left join
$sql1 = "SELECT * from student_marks LEFT JOIN student_address on student_address.sid=student_marks.sid";
$result1 = $conn->query($sql1);
//display data on web page
while($row = mysqli_fetch_array($result1)){
echo " STUDENT-ID : ". $row['sid'], " ----- SUBJECT 1 : ". $row['subject1'] ," ----- SUBJECT 2 : ". $row['subject2'] ;
echo "<br>";
}
//close the connection
$conn->close();
?>
</body>
</html>
Output :
type localhost/form2.php in browser
Similar Reads
PHP Tutorial PHP is a widely used, open-source server-side scripting language primarily designed for web development. It is embedded directly into HTML and generates dynamic content on web pages. It allows developers to handle database interactions, session management, and form handling tasks.PHP code is execute
9 min read
Top 60+ PHP Interview Questions and Answers -2025 PHP is a popular server-side scripting language, widely known for its efficiency in web development and versatility across various platforms. PHP is extensively utilized by top companies such as Facebook, WordPress, Slack, Wikipedia, MailChimp, and many more due to its robust features and high perfo
15+ min read
PHP Introduction PHP stands for Hypertext Preprocessor. It is an open-source, widely used language for web development. Developers can create dynamic and interactive websites by embedding PHP code into HTML. PHP can handle data processing, session management, form handling, and database integration. The latest versi
8 min read
PHP Arrays Arrays are one of the most important data structures in PHP. They allow you to store multiple values in a single variable. PHP arrays can hold values of different types, such as strings, numbers, or even other arrays. Understanding how to use arrays in PHP is important for working with data efficien
5 min read
PHP | Functions A function in PHP is a self-contained block of code that performs a specific task. It can accept inputs (parameters), execute a set of statements, and optionally return a value. PHP functions allow code reusability by encapsulating a block of code to perform specific tasks.Functions can accept param
8 min read
Difference between HTTP GET and POST Methods HTTP (Hypertext Transfer Protocol) specifies a collection of request methods to specify what action is to be performed on a particular resource. The most commonly used HTTP request methods are GET, POST, PUT, PATCH, and DELETE. This article covers the 2 most common HTTP request methods, i.e. the GET
4 min read
PHP Data Types In PHP, data types define the kind of value a variable can hold. PHP is a loosely typed language, meaning you don’t need to declare the data type of a variable. It is automatically assigned based on the value. But it is important to understand data types because it is important for writing reliable,
4 min read
PHP Operators In PHP, operators are special symbols used to perform operations on variables and values. Operators help you perform a variety of tasks, such as mathematical calculations, string manipulations, logical comparisons, and more. Understanding operators is essential for writing effective and efficient PH
8 min read
Creating a Registration and Login System with PHP and MySQL A registration and login system is a fundamental component of many web applications and provides user authentication and security. This allows users to create an account log in with their login credentials and manage their session securely. By using PHP for server-side scripting and MYSQL for databa
12 min read
PHP File Handling In PHP, File handling is the process of interacting with files on the server, such as reading files, writing to a file, creating new files, or deleting existing ones. File handling is essential for applications that require the storage and retrieval of data, such as logging systems, user-generated c
4 min read