<form action="insert.php" method="post">
    <p>
        <label for="jmeno">Jméno:</label>
        <input type="text" name="jmeno" id="jmeno">
    </p>
    <p>
        <label for="prijmeni">Příjmení:</label>
        <input type="text" name="prijmeno" id="prijmeni">
    </p>
    <p>
        <label for="email">Email:</label>
        <input type="text" name="email" id="email">
    </p>
    <p>
        <label for="cislo">Telefoní číslo:</label>
        <input type="text" name="cislo" id="cislo">
    </p>
    <p>
	<label for="adresa">Adresa:</label>
	<input type="text" name="adresa" id="adresa">
    </p>
    <input type="submit" value="Submit">
</form>


insert.php:

<?php
$server = "localhost";
$user = "username";
$password = "password";
$dbname = "DB";
$conn = new mysqli($server, $user, $password, $dbname);
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
$jmeno = mysqli_real_escape_string($link, $_POST['jmeno']);
$prijmeni = mysqli_real_escape_string($link, $_POST['prijmeni']);
$email = mysqli_real_escape_string($link, $_POST['email']);
$cislo = mysqli_real_escape_string($link, $_POST['cislo']);
$adresa = mysqli_real_escape_string($link, $_POST['adresa']);

$sql = "INSERT INTO sberdat (tel_cislo, jmeno, prijmeni, email, adresa)
VALUES ($cislo, $jmeno, $prijmeni, $email, $adresa)";
if ($conn->query($sql) === TRUE) {
    echo "Přidáno";
} else {
    echo "Chyba: " . $sql . "<br>" . $conn->error;
}
?>