How i can insert data to mysql from a form ?

Following through this course and studying MySQL should get you ready for creating dynamic database based website in PHP.

There are lots of simple easy solutions but that is one of the problems with PHP. There is so much old deprecated code with errors and vulnerabilities which make simple solutions difficult to trust. I would recommend taking these courses and studying them to make sure you have a well done secure connection.

Goodluck! --Ricky

it;s useless really... i know i can i insert whith line like :

<?php

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 

$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('John', 'Doe', 'john@example.com')";

if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();

But i need insert values from a box not from a file...

Here is the most recent php + databases course - but I think it uses sqlite not mysql, so maybe not useful.

Now you've got your database connection set up, you can start to work on the form side.

This course will take your through that particular aspect via the contact form tutorial.

Although the contact form doesn't connect to the database, it does tell you how to take form values and use them for functionality.

You're going to want to watch "adding a contact form" badge, but the whole course would be pretty helpful ;)