[英]One-to-one becomes one-to-many Entity Framework generating database-first
我首先生成Entity Framework數據庫(來自數據庫的EF Designer)。 我在Microsoft SQL Server中有兩個表:
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,關系顯示為一對一,因為Fk_Person_Id
設置為isUnique = true
:
Fk_Person_Id INT UNIQUE
FOREIGN KEY REFERENCES dbo.Person(Pk_Person_Id));
現在在Visual Studio中,我從數據庫中添加了一個新的ADO.NET實體數據模型 - > EF Designer - >選擇這兩個表並默認保留所有復選框選項。
生成結束后,我在Visual Studio圖中看到了這個.edmx
:
這種關系已經改變為一對多 - 為什么? 這是錯的嗎? 我不希望一個人擁有一系列護照 - 這不是我試圖描述的邏輯。
和EF代碼:
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; }
}
好吧,在數據庫模型編輯器( .edmx
文件編輯器)中,通過單擊關系(實體daigrams之間的箭頭),您可以以這種方式配置其屬性,使其為1對1(它不會更改您的數據庫) !),但隨后您可以生成創建此類數據庫所需的代碼。 結果,我得到以下內容:
-- --------------------------------------------------
-- 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
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