$scope.student = [name: "Joe", grades: "85", info: ""];

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
    //read the json file contents
    $jsondata = file_get_contents("php://input");

    //convert json object to php associative array
    $data = json_decode($jsondata, true);

    $studentname = $data['studentname'];
    $stuedentgrades = $data['stuedentgrades'];
    $studentinfo = $data['studentinfo'];

$sql = "INSERT INTO students (name, grades, info)
VALUES ('$studentname', '$stuedentgrades', '$studentinfo')";

if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>

Undefined index: info

`if(isset($_POST('info'))){

     $info= $data['info'];
}else{
    echo "NOOOOOOOOOO";
}   `