All CRUD with Example

<?php 
// MySQL Connection
$servername = "localhost"; 
$username = "root"; 
$password = ""; 
$conn = new mysqli($servername, $username, $password); 

// Check connection
if ($conn->connect_error)  
{ 
    die("Connection failed: " . $conn->connect_error); 
} 

// Create Database
$sql = "CREATE DATABASE IF NOT EXISTS Academy2"; 
$conn->query($sql); 

// Use Database
$conn->select_db("Academy2"); 

// Create Table
$table_sql = "CREATE TABLE IF NOT EXISTS Student2  
( 
    Student_ID INT AUTO_INCREMENT PRIMARY KEY, 
    Student_Name VARCHAR(100) NOT NULL, 
    Course VARCHAR(100) NOT NULL, 
    Fees INT NOT NULL 
)"; 
$conn->query($table_sql); 

// INSERT
if (isset($_POST['insert']))  
{ 
    $name = $_POST['name']; 
    $course = $_POST['course']; 
    $fees = $_POST['fees']; 
    $insert_sql = "INSERT INTO Student2 (Student_Name, Course, Fees) VALUES 
    ('$name', '$course', $fees)"; 
    $conn->query($insert_sql); 
} 

// UPDATE
if (isset($_POST['update']))  
{ 
    $id = $_POST['id']; 
    $name = $_POST['name']; 
    $course = $_POST['course']; 
    $fees = $_POST['fees']; 
    $update_sql = "UPDATE Student2 SET Course='$course' WHERE Student_ID=$id"; 
    $conn->query($update_sql); 
} 

// DELETE
if (isset($_POST['delete']))  
{ 
    $id = $_POST['id']; 
    $delete_sql = "DELETE FROM Student2 WHERE Student_ID=$id"; 
    $conn->query($delete_sql); 
} 

// SEARCH
$search_result = null; 
if (isset($_POST['search']))  
{ 
    $id = $_POST['id']; 
    $search_sql = "SELECT * FROM Student2 WHERE Student_ID=$id"; 
    $search_result = $conn->query($search_sql); 
} 
?> 

<!-- HTML Form -->
<h2>Student Form</h2> 
<form method="post"> 
    ID (for update/delete/search): <input type="number" name="id"><br><br> 
    Name: <input type="text" name="name"><br><br> 
    Course: <input type="text" name="course"><br><br> 
    Fees: <input type="number" name="fees"><br><br> 
    <input type="submit" name="insert" value="Insert"> 
    <input type="submit" name="update" value="Update"> 
    <input type="submit" name="delete" value="Delete"> 
    <input type="submit" name="search" value="Search"> 
</form> 

<?php 
if ($search_result && $search_result->num_rows > 0)  
{ 
    $row = $search_result->fetch_assoc(); 
    echo "<h3>Search Result:</h3>"; 
    echo "ID: " . $row["Student_ID"] . "<br>"; 
    echo "Name: " . $row["Student_Name"] . "<br>"; 
    echo "Course: " . $row["Course"] . "<br>"; 
    echo "Fees: " . $row["Fees"] . "<br>"; 
} 
?> 

<h2>All Students</h2> 
<table border="1" cellpadding="5" cellspacing="0"> 
<tr> 
<th>ID</th><th>Name</th><th>Course</th><th>Fees</th> 
</tr> 
<?php 
$result = $conn->query("SELECT * FROM Student2"); 
while($row = $result->fetch_assoc())  
{ 
    echo "<tr>"; 
    echo "<td>".$row['Student_ID']."</td>"; 
    echo "<td>".$row['Student_Name']."</td>"; 
    echo "<td>".$row['Course']."</td>"; 
    echo "<td>".$row['Fees']."</td>"; 
    echo "</tr>"; 
} 
?> 
</table>