一個與級聯給錯誤

我學習EF代碼第一次與遷移一對多的關係，我有3個實體：一個與級聯給錯誤

[User] 1--->* [Call] 1--->* [ETA]

代碼：

User.cs

public class User 
{ 
    [Key] 
    public int Id { get; set; } 

    public Guid LongId { get; set; } 

    [Required] 
    public string Name { get; set; } 

    public virtual ICollection<Call> Calls { get; set; } // many calls 

    public User() 
    { 
     LongId = Guid.NewGuid(); 
    } 
}

Call.cs

public class Call 
{ 
    [Key] 
    public int Id { get; set; } 

    [DatabaseGenerated(DatabaseGeneratedOption.Computed)] 
    public string BreakdownNo { get; private set; } 

    [Required,MaxLength(32)] 
    public string Customer { get; set; } 

    [Required,MaxLength(32)] 
    public string TrailerNo { get; set; } 

    [Required, MaxLength(32)] 
    public string DepotContact { get; set; } 

    [Required, MaxLength(48), RegularExpression(@"^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$")] 
    public string DepotEmail { get; set; } 

    [Required, MinLength(9), MaxLength(32)] 
    public string DepotPhone { get; set; } 

    [Required, MaxLength(32)] 
    public string DriverContact { get; set; } 

    [Required, MinLength(9), MaxLength(32), RegularExpression(@"^(7\d{3}|\(?07\d{3}\)?)\s?\d{3}\s?\d{3}$")] 
    public string DriverPhone { get; set; } 

    [Required, MaxLength(256)] 
    public string LocatedAtFreeText { get; set; } 

    [Required, MaxLength(8), RegularExpression(@"^([A-PR-UWYZ0-9][A-HK-Y0-9][AEHMNPRTVXY0-9]?[ABEHMNPRVWXY0-9]? {0,1}[0-9][ABD-HJLN-UW-Z]{2}|GIR 0AA)$")] 
    public string LocatedAtPostCode { get; set; } 

    [Required, MaxLength(16)] 
    public string StartupNo { get; set; } 

    [Required] 
    public bool IsLoaded { get; set; } 

    [Required, MaxLength(256)] 
    public string FaultDescription { get; set; } 

    [Required] 
    public DateTime StartTime { get; set; } 

    public DateTime? EndTime { get; set; } 
    public string Status { get; set; } 

    public virtual User Controller { get; set; } // 1 controller 
    public virtual ICollection<ETA> ETAs { get; set; } // many ETAs 

    public Call() 
    { 
     StartTime = DateTime.Now; 
     ETAs = new List<ETA> { new ETA() }; 
     Status = "Logged"; 
    } 
}

ETA.c

public class ETA 
{ 
    [Key] 
    public int Id { get; set; } 

    [Required] 
    public TimeSpan Value { get; set; } 

    public int CallId { get; set; } 

    public ETA() 
    { 
     Value = TimeSpan.FromMinutes(90); 
    } 
}

我想它，所以當我刪除它刪除所有Calls爲User，進而刪除所有ETAs的那些Calls的User。

當我從數據庫中刪除（使用數據庫資源管理器）的用戶排它給了我一個錯誤：

沒有行被刪除。嘗試刪除第201行時發生問題。錯誤來源：.Net SqlClient數據提供程序。錯誤消息：DELETE語句與REFERENCE約束「FK_dbo.Calls_dbo.Users_Controller_Id」衝突。衝突發生在數據庫「BreakdownDb」，表「dbo.Calls」，列'Controller_Id'。

來源

2013-01-21 sprocket12

您可以打開級聯刪除選項，在實體框架，在這裏你會找到更多的信息： http://blogs.msdn.com/b/alexj/archive/2009/08/19/tip-33-how-cascade-delete-really-works-in-ef.aspx

來源

2013-01-21 16:54:13 unjuken

我做不要認爲你的答案首先適用於代碼，但無論如何感謝。 – sprocket12

解決的辦法是OnModelCreating方法添加到我的DbContext類：

public class BreakdownDb : DbContext 
{ 
    public DbSet<Call> Calls { get; set; } 
    public DbSet<User> Users { get; set; } 

    public BreakdownDb(): base("name=DefaultConnection") {} 

    protected override void OnModelCreating(DbModelBuilder modelBuilder) 
    { 
     modelBuilder.Entity<User>().HasMany(x => x.Calls).WithRequired(); 
     modelBuilder.Entity<Call>().HasMany(x => x.ETAs).WithRequired(); 
    } 
}

來源

2013-01-22 10:52:14 sprocket12

一個與級聯給錯誤

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