mysqli why does this happens?

Question

I have two subsequent mysqli statements, and the second returns:

Fatal error: Call to a member function bind_param() on a non-object in ...

Answer 1

Something might have gone wrong with $db->prepare(), check $db->error.

Answer 2

Check the return value of mysqli::prepare. If it is FALSE, you should get the details for the occured error with mysqli::error.

Answer 3

I think your $stmt variable is null when you call bind_param over it. maybe your $_POST['vote'] is empty? you can check it before you bind the param on the command