ab.php

<!DOCTYPE HTML>  
<html>
<head>
<style>
.error {color: #FF0000;}
</style>
</head>
<body>  
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" >
problem<input type="text" name="problem">
email<input type="text" name="email">
name<input type="text" name="name">
<input type="submit" name="post">
</form>
<?php
$servername = "localhost";
$username = "root";
$password = "";
$database = "myDB";

// Create connection
$conn = new mysqli($servername, $username, $password ,$database);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 

// Create database
/*$sql = "CREATE DATABASE myDB";
if ($conn->query($sql) === TRUE) {
    echo "Database created successfully";
} else {
    echo "Error creating database: " . $conn->error;
}

// sql to create table

$sql = "CREATE TABLE MyGuests (
 
username VARCHAR(30) NOT NULL PRIMARY KEY,
problem VARCHAR(300) NOT NULL,
email VARCHAR(50),
reg_date TIMESTAMP
)";

if ($conn->query($sql) === TRUE) {
    echo "Table MyGuests created successfully";
} else {
    echo "Error creating table: " . $conn->error;
}
*/
if( $_SERVER["REQUEST_METHOD"] == "POST"){
$a = $_POST['name'];
$b = $_POST['problem'];
$c = $_POST['email'];
$sql = "INSERT INTO MyGuests (username, problem , email) VALUES ( $a, $b, $c )";

if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

}
$conn->close();
?>

</body>
</html>