ID of an inserted record

Question

I am wondering how to get the id of inserted record returned in http response to POST method

Controller method:

public HttpResponseMessage POST([FromBody]Map newmap)
{
try
  {
   using (SHATDbEntities entities = new SHATDbEntities())
    {
     entities.Maps.Add(newmap);
     entities.SaveChanges();
     var message = Request.CreateResponse(HttpStatusCode.Created, newmap);
     message.Headers.Location = new Uri(Request.RequestUri + newmap.Id.ToString());
     return message;
     }
   }
    catch (Exception ex)
   {
     return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ex);
   }
   }

Response Handled:

HttpClient client = new HttpClient();
            client.BaseAddress = new Uri("http://localhost:2351/");
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(
            new MediaTypeWithQualityHeaderValue("application/json"));
            HttpResponseMessage response = client.PostAsJsonAsync(RequestURI, newmap).Result;
int mapid = int.Parse(responsestatusCode.Content.ReadAsStringAsync().Result)

Explanation:

I tried other solution which available on stack overflow but didn't get solution and above code but it through an exception i.e here

Answer 1

If using Entity Framework and have an Identity column set as primary key on table:

Taken from this SO: How can I get Id of inserted entity in Entity framework?

Entity framework by default follows each INSERT with SELECT SCOPE_IDENTITY() when auto-generated Ids are used.

So after your .SaveChanges() call, check that your newMap object has the Id value populated on it.

If not using Entity Framework there are two solutions here: How to get last inserted id?

One is to use an OUT parameter, the other is the SCOPE_IDENTITY. Both will require changes to the underlying sql generated for your SaveChanges() method.

Your response.Content should just be a JSON representation of your newMap object. Deserialize it back to a Map and you can access it as such.

JSON deserialization should be as simple as:

var deserializedMap = 
    JsonConvert.DeserializeObject<Map>(response.Content);

You may also try:

var deserializedMap = JsonConvert.DeserializeObject<Map>(await response.Content.ReadAsJSonAsync());

Since your doing an async http request.