servicio php slim 3

//   COPIAR CODIGO A PARTIR DE ACA
//   pastebin.com/u/luidat


$app->get('/alumnos/:nombre', function($nombre){
  $sql="SELECT * FROM alumnos";
  $db=getConnection();
  $stmt=$db->query($sql);
  $alumnos=$stmt->fetchAll(PDO::FETCH_OBJ);
  echo json_encode($alumnos);
});

$app->post('/alumnos','fnpost');

function fnpost(){
    $request=\Slim\Slim::getInstance()->request();
    $body=json_decode($request->getBody());
    $sql="INSERT INTO alumnos values(null,:A, :B, :C)";
    $db=getConnection();
    $stmt=$db->prepare($sql);
    $stmt->bindParam("A",$body->nombre);
    $stmt->bindParam("B",$body->apellido);
    $stmt->bindParam("C",$body->edad);
    $stmt->execute();
    echo "Se registro elemento";
}

$app->delete('/alumnos/:code','fndelete');
function fndelete($code) {
    $sql="DELETE FROM alumnos WHERE id=:a";
    $db=getConnection();
    $stmt=$db->prepare($sql);
    $stmt->bindParam(":a",$code);
    $stmt->execute();
    echo 'The register with id '.$code.' has been deleted';
    }
function getConnection(){
$dbhost="127.0.0.1";
$dbuser="root";
$dbpass="";
$dbname="dbsidet";
$dbh = new PDO("mysql:host=$dbhost;dbname=$dbname;charset=utf8",$dbuser,$dbpass);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
return $dbh;
}

$app->run();
///       SCRIP BASE DE DATOS
/*
CREATE DATABASE IF NOT EXISTS `dbsidet` DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_spanish_ci;
USE `dbsidet`;

-- --------------------------------------------------------

--
-- Estructura de tabla para la tabla `alumnos`
--

CREATE TABLE IF NOT EXISTS `alumnos` (
  `id` int(4) NOT NULL AUTO_INCREMENT,
  `nombre` varchar(50) COLLATE utf8mb4_spanish_ci NOT NULL,
  `apellido` varchar(50) COLLATE utf8mb4_spanish_ci NOT NULL,
  `edad` int(2) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_spanish_ci AUTO_INCREMENT=9 ;

--
-- Volcado de datos para la tabla `alumnos`
--

INSERT INTO `alumnos` (`id`, `nombre`, `apellido`, `edad`) VALUES
(1, 'LUCHO', 'ALBERTO', 43),
(3, 'ENRIQUE', 'CRUZ', 38),
(4, 'JULIA', 'IGLESIAS', 23),
(5, 'ROMULO', 'ROMERO', 39),
(6, 'ALEJANDRA', 'DIAZ', 54),
(7, 'LUCHO', 'ALBERTO', 43);
*/