多対多関係のすべてのエンティティのデータを取得

Question

picture of DB私のデータベースには3つのテーブルがあります顧客、映画、顧客Filmsは顧客と映画の間のテーブルで、私は彼らが借りた映画。 私はspesific id（コード8と9）の仕事をする関数を書いています。私の質問は、すべてのエンティティにデータを表示する方法です。私のクラス

namespace MoviePro.Models 
{ 
using System; 
using System.Collections.Generic; 

public partial class Films 
{ 
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", 
"CA2214:DoNotCallOverridableMethodsInConstructors")] 
    public Films() 
    { 
     this.Customers = new HashSet<Customers>(); 
    } 

    public int FilmId { get; set; } 
    public string FilmName { get; set; } 
    public string Length { get; set; } 
    public string Genre { get; set; } 

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", 
    "CA2227:CollectionPropertiesShouldBeReadOnly")] 
    public virtual ICollection<Customers> Customers { get; set; } 
    } 
    } 
    public partial class Customers 
    { 
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", 
    "CA2214:DoNotCallOverridableMethodsInConstructors")] 
    public Customers() 
    { 
     this.Films = new HashSet<Films>(); 
    } 

    public int CustomerId { get; set; } 
    public string CustomerName { get; set; } 
    public string Address { get; set; } 
    public string City { get; set; } 
    public string Email { get; set; } 
    public string Phone { get; set; } 
    public Nullable<int> FilmId { get; set; } 

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", 
    "CA2227:CollectionPropertiesShouldBeReadOnly")] 
    public virtual ICollection<Films> Films { get; set; } 
    } 
    } 

を追加

public ActionResult GetData() 
    { 
     MyDatabaseEntities2 db = new MyDatabaseEntities2(); 
     var q = (from c in db.Customers 
       from Films in db.Films 
        where Films.FilmId == 8 
        where c.CustomerId == 9 
       select new 
       { 
        c.CustomerName, 
        c.Phone, 
        c.FilmId, 
        c.CustomerId, 
         FilmName = Films.FilmName 

       }).ToList(); 
     return Json(new { data = q }, JsonRequestBehavior.AllowGet); 
    } 

、そんなに

をありがとう****新しいコードに動作することを****

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.Mvc; 
using MoviePro.Models; 
using System.Data.Entity; 

namespace MoviePro.Controllers 
{ 
public class CustomersController : Controller 
{ 
    // GET: Customers 
    public ActionResult Index() 
    { 
     return View(); 
    } 
    public ActionResult GetData() 
    { 
     MyDatabaseEntities2 db = new MyDatabaseEntities2(); 
     var q = (from c in db.Customers 
       from Films in c.Films 
       where Films.FilmId == Films.FilmId 
       where c.CustomerId == c.CustomerId 
       select new 
       { 
        c.CustomerName, 
        c.Phone, 
        c.FilmId, 
        c.CustomerId, 
        FilmName = Films.FilmName 

       }).ToList(); 
     return Json(new { data = q }, JsonRequestBehavior.AllowGet); 
    } 

    public ActionResult loaddata() 
    { 
     MyDatabaseEntities2 dc = new MyDatabaseEntities2(); 

     var customers = dc.Customers.Select(c => new 
     { 
      c.CustomerName, 
      c.Phone, 
      c.FilmId, 
      c.CustomerId, 


     }); 

     return Json(new { data = customers }, JsonRequestBehavior.AllowGet); 

    } 

    public ActionResult AddOrEdit(int id = 0) 
    { 
     if (id == 0) 
      return View(new Customers()); 

     else 
     { 
      using (MyDatabaseEntities2 db = new MyDatabaseEntities2()) 
      { 
       return View(db.Customers.Where(x => x.CustomerId== 
    id).FirstOrDefault<Customers>()); 

      } 
     } 
    } 

    [HttpPost] 
    public ActionResult AddOrEdit(Customers customer) 
    { 
     using (MyDatabaseEntities2 db = new MyDatabaseEntities2()) 
     { 
      if (customer.CustomerId == 0) 
      { 
       db.Customers.Add(customer); 
       db.SaveChanges(); 
       return Json(new { success = true, message = "Saved 
     Successfully" }, JsonRequestBehavior.AllowGet); 
      } 
      else 
      { 
       db.Entry(customer).State = EntityState.Modified; 
       db.SaveChanges(); 
       return Json(new { success = true, message = "Updated 
     Successfully" }, JsonRequestBehavior.AllowGet); 
      } 
     } 


    } 

    [HttpPost] 
    public ActionResult Delete(int id) 
    { 
     using (MyDatabaseEntities2 db = new MyDatabaseEntities2()) 
     { 
      Customers emp = db.Customers.Where(x => x.CustomerId == 
     id).FirstOrDefault<Customers>(); 

      db.Customers.Remove(emp); 
      db.SaveChanges(); 
      return Json(new { success = true, message = "Deleted 
     Successfully" }, JsonRequestBehavior.AllowGet); 
     } 
     } 
     } 
     } 

Answer 1

基本的なLINQ多対多の関係を照会するための照会形状は次のとおりです。

from c in db.Customers 
from f in c.Films // NOT db.Films 
select new 
{ 
    Customer = c.Customername, 
    Film = f.FilmName, 
    ... 
} 

これはSelectManyのクエリ構文と同等です。結果はフラットなデータのリストなので、これは一般に「フラット化」と呼ばれます。

from c in db.Customers 
select new 
{ 
    c.Customername, 
    c. ..., 
    Films = from f in c.Films 
      select new 
      { 
       f.FilmName, 
       f. ..., 
      } 
}