c# - 一对一变成一对多 Entity Framework 生成数据库优先

Question

我首先生成 Entity Framework 数据库(来自数据库的 EF Designer)。我在 Microsoft SQL Server 中有两个表:

CREATE TABLE dbo.Person
(
    Pk_Person_Id INT IDENTITY PRIMARY KEY,
    Name VARCHAR(255),
    EmailId VARCHAR(255),
);

CREATE TABLE dbo.PassportDetails
(
    Pk_Passport_Id INT PRIMARY KEY,
    Passport_Number VARCHAR(255),
    Fk_Person_Id INT UNIQUE 
       FOREIGN KEY REFERENCES dbo.Person(Pk_Person_Id)
);

INSERT INTO dbo.Person 
VALUES ('Niraj','v.a@emails.com'),
       ('Vishwanath','v.v@emails.com'),
       ('Chetan','c.v@emails.com');
GO

INSERT INTO dbo.PassportDetails 
VALUES (101, 'C3031R33', 1), (102, 'VRDK5695', 2), (103, 'A4DEK33D', 3);
GO

SELECT * FROM dbo.Person
SELECT * FROM dbo.PassportDetails;

在 SQL Server 中，关系显示为一对一，因为 Fk_Person_Id 设置为 isUn​​ique = true:

Fk_Person_Id INT UNIQUE 
     FOREIGN KEY REFERENCES dbo.Person(Pk_Person_Id));

现在在 Visual Studio 中，我添加一个新的 ADO.NET 实体数据模型 -> 来自数据库的 EF 设计器 -> 选择这两个表并默认保留所有复选框选项。

生成结束后，我在 Visual Studio 图表 .edmx 中看到了这个:

一对多的关系发生了变化——为什么？这是错误的吗？我不希望一个人收集护照 - 这不是我要描述的逻辑。

和 EF 代码:

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

    public int Pk_Person_Id { get; set; }
    public string Name { get; set; }
    public string EmailId { get; set; }

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

public partial class PassportDetail
{
    public int Pk_Passport_Id { get; set; }
    public string Passport_Number { get; set; }
    public Nullable<int> Fk_Person_Id { get; set; }

    public virtual Person Person { get; set; }
}

上下文

public partial class LightCRMEntities : DbContext
{
    public LightCRMEntities() : base("name=LightCRMEntities")
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        throw new UnintentionalCodeFirstException();
    }

    public virtual DbSet<PassportDetail> PassportDetails { get; set; }
    public virtual DbSet<Person> People { get; set; }
}

Answer 1

那么，在数据库模型编辑器(.edmx 文件编辑器)中，通过点击一个关系(实体 daigram 之间的箭头)，您可以这样配置它的属性，使其成为 1-to -1(它不会改变你的数据库!)，但是你可以生成创建这样的数据库所需的代码。结果，我得到了以下信息:

-- --------------------------------------------------
-- Creating all tables
-- --------------------------------------------------

-- Creating table 'PassportDetails'
CREATE TABLE [dbo].[PassportDetails] (
    [Pk_Passport_Id] int  NOT NULL,
    [Passport_Number] varchar(255)  NULL
);
GO

-- Creating table 'Person'
CREATE TABLE [dbo].[Person] (
    [Pk_Person_Id] int IDENTITY(1,1) NOT NULL,
    [Name] varchar(255)  NULL,
    [EmailId] varchar(255)  NULL
);
GO

-- --------------------------------------------------
-- Creating all PRIMARY KEY constraints
-- --------------------------------------------------

-- Creating primary key on [Pk_Passport_Id] in table 'PassportDetails'
ALTER TABLE [dbo].[PassportDetails]
ADD CONSTRAINT [PK_PassportDetails]
    PRIMARY KEY CLUSTERED ([Pk_Passport_Id] ASC);
GO

-- Creating primary key on [Pk_Person_Id] in table 'Person'
ALTER TABLE [dbo].[Person]
ADD CONSTRAINT [PK_Person]
    PRIMARY KEY CLUSTERED ([Pk_Person_Id] ASC);
GO

-- --------------------------------------------------
-- Creating all FOREIGN KEY constraints
-- --------------------------------------------------

-- Creating foreign key on [Pk_Passport_Id] in table 'PassportDetails'
ALTER TABLE [dbo].[PassportDetails]
ADD CONSTRAINT [FK__PassportD__Pk_Pa__5BE2A6F2]
    FOREIGN KEY ([Pk_Passport_Id])
    REFERENCES [dbo].[Person]
        ([Pk_Person_Id])
    ON DELETE NO ACTION ON UPDATE NO ACTION;
GO