實體框架4.2代碼優先流利的api映射中間表

Question

如何使用代碼優先和流利的api設置這些表關係的映射？

我對創建的所有三個實體都有一個poco，但大多數人沒有「中間」表的poco（PlanUser），所以我找不到一個很好的例子。我要告訴EF到PlanUser.PlanCustomerId列映射到Plan.CustomerId但它要麼不返回當前設置正確的結果，或作爲計劃映射引發錯誤：

"The specified association foreign key columns 'CustomerId' are invalid. The number of columns specified must match the number of primary key columns."

public class PlanUserMap : EntityTypeConfiguration<PlanUser> 
{ 
    public PlanUserMap() 
    { 
     this.ToTable("PlanUser"); 
     this.HasKey(c => new { c.CustomerId, c.PlanCustomerId }); 

     this.HasRequired(c => c.Plan).WithMany().HasForeignKey(x => x.CustomerId).WillCascadeOnDelete(false); 
     this.HasRequired(c => c.Customer).WithMany().HasForeignKey(x => x.CustomerId).WillCascadeOnDelete(false); 
    } 
} 

public class PlanMap : EntityTypeConfiguration<Plan> 
{ 
    public PlanMap() 
    { 
     this.ToTable("Plan"); 
     this.HasKey(c => c.CustomerId); 
     // the below line returns only 1 row for any given customer even if there are multiple PlanUser rows for that customer 
     //this.HasMany(c => c.PlanUsers).WithRequired().HasForeignKey(c => c.PlanCustomerId); 
     // this throws an error 
     this.HasMany(c => c.PlanUsers).WithMany().Map(m => m.MapLeftKey("PlanCustomerId").MapRightKey("CustomerId")); 
    } 
} 

public partial class CustomerMap : EntityTypeConfiguration<Customer> 
{ 
    public CustomerMap() 
    { 
     this.ToTable("Customer"); 
     this.HasKey(c => c.Id); 
     this.HasMany(c => c.PlanUsers).WithRequired().HasForeignKey(c => c.CustomerId); 
    } 
} 

---

@Slauma，SQL簡介r顯示正在執行的這些查詢。第二個應該包括除了客戶ID 1之外的客戶ID 43，但它不包括。我不知道爲什麼它沒有檢索第二行。

exec sp_executesql N'SELECT 
[Extent1].[CustomerId] AS [CustomerId], 
[Extent1].[PlanCustomerId] AS [PlanCustomerId], 
[Extent1].[CreatedOnUtc] AS [CreatedOnUtc], 
[Extent1].[IsSelected] AS [IsSelected], 
[Extent1].[IsDeleted] AS [IsDeleted], 
[Extent1].[AccessRights] AS [AccessRights] 
FROM [dbo].[PlanUser] AS [Extent1] 
WHERE [Extent1].[CustomerId] = @EntityKeyValue1',N'@EntityKeyValue1 int',@EntityKeyValue1=43 

exec sp_executesql N'SELECT 
[Extent1].[CustomerId] AS [CustomerId], 
[Extent1].[Name] AS [Name], 
[Extent1].[PlanTypeId] AS [PlanTypeId], 
[Extent1].[OrderId] AS [OrderId], 
[Extent1].[CreatedOnUtc] AS [CreatedOnUtc], 
[Extent1].[IsActive] AS [IsActive] 
FROM [dbo].[Plan] AS [Extent1] 
WHERE [Extent1].[CustomerId] = @EntityKeyValue1',N'@EntityKeyValue1 int',@EntityKeyValue1=1 

這是導致查詢執行的C＃代碼：

public List<Plan> GetPlans() 
    { 
     List<Plan> plans = new List<Plan>(); 

     // add each plan they have access rights to to the list 
     foreach (var accessiblePlan in Customer.PlanUsers) 
     { 
      plans.Add(accessiblePlan.Plan); 
     } 

     return plans; 
    } 

Answer 1

好吧，我想通了。感謝@Slauma的幫助！我們使用IOC（autofac）的存儲庫模式。我不應該在我的存儲庫服務中首先呼叫Customer.PlanUsers。我們開始解決在存儲庫服務中使用IOC的Customer實體，以快速獲取某些客戶屬性並將其置於只讀變量中。這不可避免地影響了我們，因爲我們不是實際詢問實體存儲庫，而是從實體開始，期望它充滿我們需要的所有事物，而不是預先填充的實體。

public List<Plan> GetPlans() 
    { 
     List<Plan> plans = new List<Plan>(); 
     var list = _planUserRepository.Table.Where(a => a.CustomerId == Customer.Id).ToList(); 
     foreach (var planUser in list) 
     { 
      plans.Add(planUser.Plan); 
     } 
    } 

Answer 2

我想你需要的是實際上比你試圖映射簡單：

public class PlanUserMap : EntityTypeConfiguration<PlanUser> 
{ 
    public PlanUserMap() 
    { 
     this.ToTable("PlanUser"); 
     this.HasKey(pu => new { pu.CustomerId, pu.PlanCustomerId }); 

     this.HasRequired(pu => pu.Customer) 
      .WithMany(c => c.PlanUsers) 
      .HasForeignKey(pu => pu.CustomerId) 
      .WillCascadeOnDelete(false); 

     this.HasRequired(pu => pu.Plan) 
      .WithMany(p => p.PlanUsers) 
      .HasForeignKey(pu => pu.PlanCustomerId) 
      .WillCascadeOnDelete(false); 
    } 
} 

public class PlanMap : EntityTypeConfiguration<Plan> 
{ 
    public PlanMap() 
    { 
     this.ToTable("Plan"); 
     this.HasKey(p => p.CustomerId); 
    } 
} 

public partial class CustomerMap : EntityTypeConfiguration<Customer> 
{ 
    public CustomerMap() 
    { 
     this.ToTable("Customer"); 
     this.HasKey(c => c.Id); 
    } 
} 

我不是確定你爲什麼禁用級聯刪除。我可能不會這樣做（即我將刪除兩個關係的WillCascadeOnDelete(false)），因爲關聯實體PlanUser是依賴於其他兩個實體的類型。

以下是有關這種模型（有時稱爲「與酬許多一對多的關係」）多一點細節：Create code first, many to many, with additional fields in association table