I'm trying to do a query in PHP and MYSQL, but it does not work for me,
'grado' is a number, for example 2. If I make the query only with
'grado' if it works, but if I try with
'grupo' which is a letter, for example B, it does not work, it is as if it did not detect the letters of the alphabet.
$grado=$_GET['grado']; $grupo=$_GET['grupo']; $sql = "* FROM usuarios WHERE grado = $grado AND grupo = $grupo"; $result = $conn->query($sql);