I have a problem with Serialization of Data from database to JSON format. I'm using WebAPI 2 and Entity Framework 6. I've created with EF a Model. The database and the tables with content are even created. 
When I use the code below I'm getting an error when I type <http://localhost:54149/api/qr_group> .

Controller:

```
private EfContext db = new EfContext();

// GET api/<controller>
public IEnumerable<QR_Group> GetGroups()
{
    var result = from g in db.QR_Groups
                 select g;
    return result.ToList();
}

```

I don't know how to use Newtonsoft.Json to serialize the table with the content in JSON format.

I've tried the following code instead of the code above:

```
public IQueryable<QR_Group> GetGroups()
{
  var groupList = (from g in db.QR_Groups
                   select new
                   {
                     name = g.name,
                     code = g.code
                   }).AsQueryable();

  var json = JsonConvert.SerializeObject(groupList);

  return json; //error CS0029: Cannot implicitly convert type `string' to `System.Linq.IQueryable<RestApi.Models.QR_Group>'
}

```

I get the error CS0029.. How can I solve this to return the data in json? As reminder: The QR\_Group entity has 3 columns (Id, name, code)