How to select specific columns in one-to-one relationship table along with few direct columns in Ent-CodePudding

I am not able to select a few direct columns along with a few specific columns in the One to One relationship table in the Entity Framework with Fluent API.

public class Employee
{
    public int id;
    public string FirstName;
    public string LastName;
    public Address address;
}

public class Address
{
    public int AId;
    public string City;
    public string PinCode;
    public string District;
    public State State;
}

public class State
{
    public int Sid;
    public string Name;
    public string CapitalCity;
}

I want to get a JSON object response like this:

{
  "Id": 1,
  "FirstName": "John",
  "Address": {
    "AId": 1,
    "City": "San Francisco",
    "State": {
      "Sid": 1,
      "Name": "California"
    }
  }
}

I am currently doing

this.context.Employees
            .Select(employee => new Employee
                                    {
                                        Id  = employee.Id;,
                                        FirstName  = employee.FirstName;
                                        Address = employee.Address.select(*I am struggling here*);
                                        State = employee.Address.State.select(*I am struggling here*);
                                        Id  = employee.Id;
                                    })
            .AsNoTracking()
            .FirstOrDefaultAsync();

Can I include the field in that inner select of one-to-one navigation reference. ?

Is it the right way to select inner one-to-one relationship columns..?

How do I select the columns as exactly as my JSON response?

CodePudding user response：

If you do not have appropriate DTO, better project to anonymous class:

var result = his.context.Employees
    .Select(employee => new
    {
        employee.Id,
        employee.FirstName,
        Address = new 
        { 
            employee.Address.AId,
            employee.Address.City,
            State = new 
            {
                employee.Address.State.Sid,
                employee.Address.State.Name
            }
        }
    })
   .FirstOrDefaultAsync();

Note that AsNotracking() is not needed if you have custom projection via Select, EF do not track custom objects.