Peringatan:mysqli_query() mengharapkan parameter 1 diberikan boolean mysqli

Kemungkinan besar, Anda memiliki kesalahan koneksi di mysqli_connect. Kredensial salah atau MySQL sedang down.

if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
    //you need to exit the script, if there is an error
    exit();
}