Need Help, Database problems, Urgent for school!

xl97:
Thats odd..

The ID column doesnt look like an auto-incrementing value.

And if this is truly the case.. then why is the PHP script looking for one?

$a=$_GET['ID'];

&
$sql = "INSERT INTO Essai VALUES('$a','$b','$c')";

It is an auto-increment value, ID is removable i forgot to remove it, it's unnecessary.
See the command i put in the arduino program, i didn't put the 'ID' and it's value.
Those numbers, i added them by myself, the ID numbers,if i don't put anything it auto increment the number automatically.

xl97:
Can you elaborate on this comment you made: "Only me can access the database"

Q: How so? What criteria/protocols are in place that only you (somehow) have a magic browser that logs DB entries?

A: It's not about my magic browser or something, it's locked by a password and a username only me can me can access it, that's it.