Question

我对MVC很新，我在阅读两个模型之间的相关数据时遇到了问题，这两个模型没有导航属性。我查看了以下主题，但没有任何运气： MVC4 how to load related data without Navigation Properties

这是我项目的一些图片的链接： http://s1067.photobucket.com/user/TimRH/slideshow/

我错过了什么或做错了什么？我的结果是空回来了

我希望有人可以帮助我朝着正确的方向前进

Answer 1

您需要在表之间创建一对多的关系

https://www.asp.net/mvc/overview/older-versions/getting-started-with-ef-5-using-mvc-4/creating-an-entity-framework-data-model-for-an-asp-net-mvc-application

主表

    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int MAINTABLENAMEID { get; set; }

    public virtual ICollection<CHILDTABLE> ALIAS { get; set; }

子表（添加导航属性）

    [ForeignKey("ALIAS")]
    public int [MAINTABLENAMEID] { get; set; }

    public virtual [MAINTABLE] ALIAS { get; set; }

如果您无权更改数据库

您可以在SMSS中测试查询是否有效

using (var db = new ApplicationDbContext())
{
    string Query = @"SELECT  C.KritWert ,C.ArtNr,C.DLNr,C.SA
        ,C.Reserviert,C.GenArtNr,C.LKZ,C.LfdNr,C.SortNr,C.KritNr
        ,C.Exclude,C.AnzSofort,C.pk,k.KritWert,k.Amount,k.Brand
        ,k.Model,k.Type_Description
    FROM C400_Article_Search_Tree_Allocation C
        JOIN Ktype K
            ON Convert(int,C.KritWert) = k.KritWert");

   ObjectQuery<[NEWMODEL]> query = new ObjectQuery<[NEWMODEL]>
                               (Query,db, MergeOption.NoTracking);
}

Answer 2

主要型号：

    namespace CrossTest_V2.Models
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;

    public partial class C400_Article_Search_Tree_Allocation
    {
        public string ArtNr { get; set; }
        public Nullable<int> DLNr { get; set; }
        public Nullable<int> SA { get; set; }
        public string Reserviert { get; set; }
        public Nullable<int> GenArtNr { get; set; }
        public string LKZ { get; set; }
        public Nullable<int> LfdNr { get; set; }
        public Nullable<int> SortNr { get; set; }
        public Nullable<int> KritNr { get; set; }
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public string KritWert { get; set; }
        public Nullable<int> Exclude { get; set; }
        public Nullable<int> AnzSofort { get; set; }
        public int pk { get; set; }

        public virtual ICollection<Ktype> Ktype { get; set; }
    }
}

儿童模特：

namespace CrossTest_V2.Models
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;

    public partial class Ktype
    {
        [ForeignKey("KritWert")]
        public int KritWert { get; set; }
        public Nullable<int> Amount { get; set; }
        public string Brand { get; set; }
        public string Model { get; set; }
        public string Type_Description { get; set; }

        public virtual C400_Article_Search_Tree_Allocation C400Ktype { get; set; }
    }
}

视图模型：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
using CrossTest_V2.Models;

namespace CrossTest_V2.ViewModels
{
    public class CrossViewModel : DbContext
    {
        public List<Cross> Crosses { get; set; }
        public List<C203_Reference_Numbers> Refnr { get; set; }
        public List<C203_Reference_Numbers> Refnr2 { get; set; }
        public List<C400_Article_Search_Tree_Allocation> C400 { get; set; }
        public List<C400_Article_Search_Tree_Allocation> C400_2 { get; set; }
    }
}

控制器：

 TCDEntities db = new TCDEntities();

    public ActionResult Index()
    {
        CrossViewModel vm = new CrossViewModel();

        vm.Crosses = db.Crosses.Take(1).ToList();

        Cross cross = db.Crosses.FirstOrDefault();

        // List<C400_Article_Search_Tree_Allocation> C400 = db.C400_Article_Search_Tree_Allocation.Where(k => k.ArtNr == cross.Article_From && k.DLNr == cross.Supplier_From && k.KritNr == 2).ToList();

        vm.Refnr = db.C203_Reference_Numbers.Where(r => r.ArtNr == cross.Article_From && r.DLNr == cross.Supplier_From).ToList();
        vm.Refnr2 = db.C203_Reference_Numbers.Where(r => r.ArtNr == cross.Article_To && r.DLNr == cross.Supplier_To).ToList();

        // C400_Article_Search_Tree_Allocation article = db.C400_Article_Search_Tree_Allocation.Where(k => k.ArtNr == cross.Article_From && k.DLNr == cross.Supplier_From && k.KritNr == 2);

        vm.C400 = db.C400_Article_Search_Tree_Allocation.Where(k => k.ArtNr == cross.Article_From && k.DLNr == cross.Supplier_From && k.KritNr == 2).ToList();
        vm.C400_2 = db.C400_Article_Search_Tree_Allocation.Where(k => k.ArtNr == cross.Article_To && k.DLNr == cross.Supplier_To && k.KritNr == 2).ToList();

        //var C400Ktype = db.C400_Article_Search_Tree_Allocation.Where(k => k.ArtNr == cross.Article_From && k.DLNr == cross.Supplier_From && k.KritNr == 2).ToList();

        return View(vm);
    }

读取模型之间的相关数据，这些数据在MVC4中没有导航属性

2 个答案: