C# – Web API Post returns 415 – Unsupported Media Type

How should one carry out CRUD operations on a SQL Server database using C#?

For example, let's say there is a DB table Employees with these columns:

EmployeeID, FirstName, PostalCode

and I wish to post a new employee with info to that database. What would be an efficient method to accomplish this?

My current HttpPost:

namespace API.Controllers
{
    public class EmployeesController : ApiController
    {
        [HttpPost]
        public void AddEmployee (Employee employee)
        {
            SqlConnection myConnection = new SqlConnection();
            myConnection.ConnectionString = @"Server=.\servername;Database=Northwind;User ID=Username;Password=password;";

            SqlCommand sqlCmd = new SqlCommand();
            sqlCmd.CommandType = CommandType.Text;
            sqlCmd.CommandText = "INSERT INTO Employee (EmployeeID,FirstName,PostalCode) Values (@EmployeeID, @FirstName, @Zip)";

            sqlCmd.Parameters.AddWithValue("@EmployeeID", employee.EmployeeID);
            sqlCmd.Parameters.AddWithValue("@FirstName", employee.FirstName);
            sqlCmd.Parameters.AddWithValue("@Zip", employee.Zip);

            myConnection.Open();
            int rowInserted = sqlCmd.ExecuteNonQuery();
            myConnection.Close();
        }
    }
}

And here is the Employee model:

namespace API.Models
{
    public class Employee
    {
        public int EmployeeID { get; set; }
        public string FirstName { get; set; }
        public int Zip { get; set; }
    }
}

When I test my API with Fiddler with the following input:

{ "EmployeeID":91, "FirstName":"Vader", "Zip":94221}

I get this error:

HTTP/1.1 415 Unsupported Media Type

and nothing is inserted into the database.

Any guidance would be greatly appreciated.

WebApiConfig.cs:

namespace API
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services

            // Web API routes
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }
    }
}

The raw error message generated, as per request:

HTTP/1.1 415 Unsupported Media Type

Cache-Control: no-cache

Pragma: no-cache

Content-Type: application/json; charset=utf-8

Expires: -1

Server: Microsoft-IIS/10.0

X-AspNet-Version: 4.0.30319

X-SourceFiles: =?UTF-8?B?YzpcdXNlcnNcYW1lc2tvXGRvY3VtZW50c1x2aXN1YWwgc3R1ZGlvIDIwMTVcUHJvamVjdHNcQVBJXEFQSVxhcGlcRW1wbG95ZWVzXEFkZEVtcGxveWVl?=

X-Powered-By: ASP.NET

Date: Fri, 22 Jul 2016 15:33:06 GMT

Content-Length: 986

{"Message":"The request contains an entity body but no Content-Type header. The inferred media type 'application/octet-stream' is not supported for this resource.",

"ExceptionMessage":"No MediaTypeFormatter is available to read an object of type 'Employee' from content with media type 'application/octet-stream'.",

"ExceptionType":"System.Net.Http.UnsupportedMediaTypeException",

"StackTrace":" at System.Net.Http.HttpContentExtensions.ReadAsAsync[T](HttpContent content, Type type, IEnumerable1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)\r\n at System.Net.Http.HttpContentExtensions.ReadAsAsync(HttpContent content, Type type, IEnumerable1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)\r\n at System.Web.Http.ModelBinding.FormatterParameterBinding.ReadContentAsync(HttpRequestMessage request, Type type, IEnumerable`1 formatters, IFormatterLogger formatterLogger, CancellationToken cancellationToken)"}