MySql: Insert values in an auto_increment field with PHP - php

Question

What I'm actually trying to do is insert a row with:
INSERT INTO users VALUES (col1, col2, ...)
where col1 is an auto_increment.
The PHP code is:
<?php
$host = "http://name.altervista.org/";
$user = "name";
$psw = "";
$db = "my_name";
$response = array();
$response["success"] = true;
$connessione = new mysqli($host, $user, $psw, $db);
if($connessione->connect_errno == 0)
{
$nome = $_POST["nome"];
$cognome = $_POST["cognome"];
$username = $_POST["username"];
$password = $_POST["password"];
$nTelefono = $_POST["nTelefono"];
$email = $_POST["email"];
$sql = "INSERT INTO users
VALUES (DEFAULT, '$nome', '$cognome', '$username', '$password', '$nTelefono', '$email')";
$ris = $connessione->query($sql);
if($connessione->affected_rows == 1)
{
echo(json_encode($response));
}
else
{
$response["success"] = false;
echo(json_encode($response));
}
}
else
{
$response["success"] = false;
echo(json_encode($response));
}
?>
I search similar questions here in stackoverflow, and I try to use DEFAULT or NULL, but it doesn't work. And if I put a number instead of the default value that is not already in the table it works, so I really don't understand where the problem is.
Have you any other suggestions?
EDIT: The table structure on the database:
click
EDIT 2: I tried to delete the table and create it again, and now it works with the NULL thing. Thanks for the support!

Answer 1

When you are doing an insert, list all the columns being inserted. You seem to want:
INSERT INTO users (nome, cognome, username, password, nTelefono, email)
VALUES ('$nome', '$cognome', '$username', '$password', '$nTelefono', '$email');
Next. Never store clear-text passwords in the database. You should be encrypting the value on the client side so the values are never passed over the network.
Next. Learn to use parameterized queries. When you munge query strings with parameter values, your are asking for inexplicable syntax errors and making the code subject to SQL injection attacks.

Answer 2

From the Mysql docs
INSERT INTO users VALUES ('$nome', '$cognome', '$username', '$password', '$nTelefono', '$email')";
The auto_increment fields doesn't need to be set in an INSERT statement

Answer 3

In MySQL, if you have an auto_increment column you don't need to put it in the insert statement.
Example:
You have the table:
CREATE TABLE test (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(30) NOT NULL
);
Your SQL statement should be:
INSERT INTO test(name) VALUES ('My name');