EF6 SQLEXCEPTION:PRIMARY KEY约束违反......重复的键值是(0)

问题描述 投票:0回答:2

我知道SQL,但我很新的ORM,并在2017年VS使用的EntityFramework 6.2.0我认为该框架应使我能写多少有点像我会用POCO对象沙箱发挥,而不必应付主/外键。而变化,只要我调用下面的代码context.SaveChanges()保存在数据库中;我该怎么办(还)没有与EF6及其文档明白了吗?

我创建了两个表的人,并视对方有外键WorkingHours和1:N的关系。

  CREATE TABLE [dbo].[Person](
    [FirstName] [nvarchar](100) NOT NULL,
    [LastName] [nvarchar](100) NOT NULL,
    [BirthDate] [date] NULL,
    [Id] [int] IDENTITY(1,1) NOT NULL,
 CONSTRAINT [PK_Person] PRIMARY KEY CLUSTERED 
(
    [Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

CREATE TABLE [dbo].[WorkingHours](
  [Id] [int] NOT NULL,
  [PersonId] [int] NOT NULL,
  [Date] [date] NOT NULL,
  [Start] [time](7) NOT NULL,
  [Hours] [real] NOT NULL,
 CONSTRAINT [PK_WorkingHours] PRIMARY KEY CLUSTERED 
(
  [Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

我创建从数据库模型。

我试图创建两个人物条目,每一个条目WorkingHours,并立即将其保存到数据库中。下面是代码:

     static void Main(string[] args)
    {
        using(var context = new EntityFrameworkTrialEntities2())
        {
             // Inserting entries
            var person1 = new Person() { FirstName = "Al", LastName = "Curie", BirthDate = new DateTime(1867, 11, 7) };
            var person2 = new Person() { FirstName = "Al", LastName = "Capone", BirthDate = new DateTime(1899, 1, 7) };
            context.Person.Add(person1);
            context.Person.Add(person2);

            var workingHour1 = new WorkingHour() { Date = new DateTime(1887, 8, 18), Start = new TimeSpan(6, 35, 33), Hours = 4.3F };
            var workingHour2 = new WorkingHour() { Date = new DateTime(1919, 9, 19), Start = new TimeSpan(10, 23, 56), Hours = 3.2F };
            person2.WorkingHours.Add(workingHour1); 
            person1.WorkingHours.Add(workingHour2); 

            context.WorkingHours.Add(workingHour1);
            context.WorkingHours.Add(workingHour2);
            context.SaveChanges(); // <-- place of exeception !!!!!!!!!!!!!!!!!!!!

            // (next step as EF6 trial: here the previously intentionally mixed relationships between person1/2 and workingHour2/1 shall be corrected)

但在调用context.SaveChanges();我得到这个异常:

SQLEXCEPTION:PRIMARY KEY约束 'PK_WorkingHours' 的相关规定。不能插入对象“dbo.WorkingHours”重复键。重复的密钥值是(0)。该语句已终止。**

我尝试不同的方式与更多的context.SaveChanges()和附加()等订单,但我上面的异常故障始终。 context.Configuration.ProxyCreationEnabled设置为true为默认值。

这里的模型类:

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

    public string FirstName { get; set; }
    public string LastName { get; set; }
    public Nullable<System.DateTime> BirthDate { get; set; }
    public int Id { get; set; }

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


public partial class WorkingHour
{
    public int Id { get; set; }
    public int PersonId { get; set; }
    public System.DateTime Date { get; set; }
    public System.TimeSpan Start { get; set; }
    public float Hours { get; set; }

    public virtual Person Person { get; set; }
}
c# visual-studio-2017 entity-framework-6 sqlexception
2个回答
2
投票

第一个问题是WorkingHour的主键是不是这就是为什么它总是被设置为Identity Key0int的默认值)为每WorkingHour,因此它被复制。

所以使Id WorkingHour [Id] [int] IDENTITY(1,1) NOT NULL

第二个问题是下面几行:

person2.WorkingHours.Add(workingHour1); // adding with person
person1.WorkingHours.Add(workingHour2); // adding with person

context.WorkingHours.Add(workingHour1); // adding individually
context.WorkingHours.Add(workingHour2); // adding individually

在这里,您可在上下文两次加入WorkingHour。一个与Person实体和其他可单独。因此,删除第二组,只是使用第一套如下:

person2.WorkingHours.Add(workingHour1); 
person1.WorkingHours.Add(workingHour2);

1
投票

我觉得你的问题是因为在[Id] [WorkingHours]的:

  CREATE TABLE [dbo].[WorkingHours](
      [Id] [int] NOT NULL,
      [PersonId] [int] NOT NULL,
      [Date] [date] NOT NULL,
      [Start] [time](7) NOT NULL,
      [Hours] [real] NOT NULL,
     CONSTRAINT [PK_WorkingHours] PRIMARY KEY CLUSTERED 
    (
      [Id] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY]

如下更改,然后再试一次。

 CREATE TABLE [dbo].[WorkingHours](
      [Id] [int] IDENTITY(1,1) NOT NULL,
      [PersonId] [int] NOT NULL,
      [Date] [date] NOT NULL,
      [Start] [time](7) NOT NULL,
      [Hours] [real] NOT NULL,
     CONSTRAINT [PK_WorkingHours] PRIMARY KEY CLUSTERED 
    (
      [Id] ASC
    )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
    ) ON [PRIMARY]
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