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AOD.NET Entity Framework 实体框架学习（2 模型和映射）

MSDN中的《生成模型和映射章节》

实体框架应用程序和服务基于以三种基于 XML 的语言表示的模型和映射信息：

概念架构定义语言 (CSDL)

存储架构定义语言 (SSDL)

映射规范语言 (MSL)

CSDL 将应用程序数据表示为概念模型中的一组实体和关系，它是实体数据模型的实现。以 SSDL 表示的存储模型表示数据存储的架构。上述两种模型之间的映射以 MSL 表示。

ADO.NET 实体数据模型工具可自动生成应用程序的 CSDL、SSDL 和 MSL 内容。实体数据模型向导从现有数据库生成模型和映射信息以及数据类。然后，可以使用 ADO.NET 实体数据模型设计器（实体设计器）以图形方式修改模型和映射信息。或者，可以使用实体设计器以图形方式创建一个概念模型，接着使用 “生成数据库”向导（实体数据模型工具）自动生成支持此概念模型的存储模型、映射、数据类和数据库。在任一方案中，当基础数据库发生更改时，您都可以使用模型更新向导（实体数据模型工具）更新模型和映射信息。

EDM 生成器 (EdmGen.exe) 是一种命令行工具，通过此工具，您可以生成简单的概念模型，在该模型中实体与数据源中的表之间具有一对一的映射关系。您还可以使用 EdmGen.exe 验证概念模型，并生成基于模型中的实体类型的数据类。EdmGen.exe 是 .NET Framework 版本 3.5 Service Pack 1 (SP1) 或更高版本中的实体框架运行时组件的一部分。

这部分介绍了一下生成实体模型的时候所需要的三个文件CSDL、SSDL、MSL。其中也说明了有工具来自动生成这三文件的个内容。一个是在项目中通过《实体数据模型向导》来生成，并且可以通过《ADO.NET 实体数据模型设计器》来以图形方式来修改模型和映射信息。另一个工具是通过EDM生成器命令行工具来生成简单的概念模型。我们这里没必要使用这个命令行工具了，有强大的界面向导工具为什么不用呢？！

当您使用实体数据模型工具从现有数据库生成概念模型时，需要考虑以下注意事项：

所有实体都必须具有键。如果数据库中有一个未设置主键的表，那么实体数据模型工具会尝试为相应的实体推断一个键。此外，实体数据模型工具会在存储架构中生成一个 DefiningQuery 元素，使此实体的数据为只读。若要使此实体数据成为可更新数据，必须确认所生成的键是有效键，然后删除 DefiningQuery 元素。

仅包含外键、表示数据库中两个表之间的多对多关系的表（有时称为纯联接表）在概念模型中没有对应的实体。当实体数据模型工具遇到此类表时，会在概念模型中将该表表示为一个多对多关联，而不是实体。这种行为的一个示例就是 School 模型中的 CourseInstructor 关联。

看到上面红色字体的注意事项！一个是注意主键，一个是注意外键！

要想创建模型，得有个数据库才行。这里使用MSDN上面的School示例数据库。数据库代码如下：

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

USE [master];
GO

IF EXISTS (SELECT * FROM sys.databases WHERE name = 'School')
    DROP DATABASE School;
GO

-- Create the School database.
CREATE DATABASE School;
GO

-- Specify a simple recovery model 
-- to keep the log growth to a minimum.
ALTER DATABASE School 
    SET RECOVERY SIMPLE;
GO

USE School;
GO

-- Create the Department table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[Department]') 
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[Department](
    [DepartmentID] [int] NOT NULL,
    [Name] [nvarchar](50) NOT NULL,
    [Budget] [money] NOT NULL,
    [StartDate] [datetime] NOT NULL,
    [Administrator] [int] NULL,
CONSTRAINT [PK_Department] PRIMARY KEY CLUSTERED 
(
    [DepartmentID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

-- Create the Person table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[Person]') 
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[Person](
    [PersonID] [int] IDENTITY(1,1) NOT NULL,
    [LastName] [nvarchar](50) NOT NULL,
    [FirstName] [nvarchar](50) NOT NULL,
    [HireDate] [datetime] NULL,
    [EnrollmentDate] [datetime] NULL,
CONSTRAINT [PK_School.Student] PRIMARY KEY CLUSTERED 
(
    [PersonID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

-- Create the OnsiteCourse table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[OnsiteCourse]') 
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[OnsiteCourse](
    [CourseID] [int] NOT NULL,
    [Location] [nvarchar](50) NOT NULL,
    [Days] [nvarchar](50) NOT NULL,
    [Time] [smalldatetime] NOT NULL,
CONSTRAINT [PK_OnsiteCourse] PRIMARY KEY CLUSTERED 
(
    [CourseID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

-- Create the OnlineCourse table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[OnlineCourse]') 
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[OnlineCourse](
    [CourseID] [int] NOT NULL,
    [URL] [nvarchar](100) NOT NULL,
CONSTRAINT [PK_OnlineCourse] PRIMARY KEY CLUSTERED 
(
    [CourseID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

--Create the StudentGrade table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[StudentGrade]') 
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[StudentGrade](
    [EnrollmentID] [int] IDENTITY(1,1) NOT NULL,
    [CourseID] [int] NOT NULL,
    [StudentID] [int] NOT NULL,
    [Grade] [decimal](3, 2) NULL,
CONSTRAINT [PK_StudentGrade] PRIMARY KEY CLUSTERED 
(
    [EnrollmentID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

-- Create the CourseInstructor table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[CourseInstructor]') 
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[CourseInstructor](
    [CourseID] [int] NOT NULL,
    [PersonID] [int] NOT NULL,
CONSTRAINT [PK_CourseInstructor] PRIMARY KEY CLUSTERED 
(
    [CourseID] ASC,
    [PersonID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

-- Create the Course table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[Course]') 
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[Course](
    [CourseID] [int] NOT NULL,
    [Title] [nvarchar](100) NOT NULL,
    [Credits] [int] NOT NULL,
    [DepartmentID] [int] NOT NULL,
CONSTRAINT [PK_School.Course] PRIMARY KEY CLUSTERED 
(
    [CourseID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

-- Create the OfficeAssignment table.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[OfficeAssignment]')
        AND type in (N'U'))
BEGIN
CREATE TABLE [dbo].[OfficeAssignment](
    [InstructorID] [int] NOT NULL,
    [Location] [nvarchar](50) NOT NULL,
    [Timestamp] [timestamp] NOT NULL,
CONSTRAINT [PK_OfficeAssignment] PRIMARY KEY CLUSTERED 
(
    [InstructorID] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
END
GO

-- Define the relationship between OnsiteCourse and Course.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
       WHERE object_id = OBJECT_ID(N'[dbo].[FK_OnsiteCourse_Course]')
       AND parent_object_id = OBJECT_ID(N'[dbo].[OnsiteCourse]'))
ALTER TABLE [dbo].[OnsiteCourse]  WITH CHECK ADD  
       CONSTRAINT [FK_OnsiteCourse_Course] FOREIGN KEY([CourseID])
REFERENCES [dbo].[Course] ([CourseID])
GO
ALTER TABLE [dbo].[OnsiteCourse] CHECK 
       CONSTRAINT [FK_OnsiteCourse_Course]
GO

-- Define the relationship between OnlineCourse and Course.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
       WHERE object_id = OBJECT_ID(N'[dbo].[FK_OnlineCourse_Course]')
       AND parent_object_id = OBJECT_ID(N'[dbo].[OnlineCourse]'))
ALTER TABLE [dbo].[OnlineCourse]  WITH CHECK ADD  
       CONSTRAINT [FK_OnlineCourse_Course] FOREIGN KEY([CourseID])
REFERENCES [dbo].[Course] ([CourseID])
GO
ALTER TABLE [dbo].[OnlineCourse] CHECK 
       CONSTRAINT [FK_OnlineCourse_Course]
GO

-- Define the relationship between StudentGrade and Course.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
       WHERE object_id = OBJECT_ID(N'[dbo].[FK_StudentGrade_Course]')
       AND parent_object_id = OBJECT_ID(N'[dbo].[StudentGrade]'))
ALTER TABLE [dbo].[StudentGrade]  WITH CHECK ADD  
       CONSTRAINT [FK_StudentGrade_Course] FOREIGN KEY([CourseID])
REFERENCES [dbo].[Course] ([CourseID])
GO
ALTER TABLE [dbo].[StudentGrade] CHECK 
       CONSTRAINT [FK_StudentGrade_Course]
GO

--Define the relationship between StudentGrade and Student.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
       WHERE object_id = OBJECT_ID(N'[dbo].[FK_StudentGrade_Student]')
       AND parent_object_id = OBJECT_ID(N'[dbo].[StudentGrade]'))
ALTER TABLE [dbo].[StudentGrade]  WITH CHECK ADD  
       CONSTRAINT [FK_StudentGrade_Student] FOREIGN KEY([StudentID])
REFERENCES [dbo].[Person] ([PersonID])
GO
ALTER TABLE [dbo].[StudentGrade] CHECK 
       CONSTRAINT [FK_StudentGrade_Student]
GO

-- Define the relationship between CourseInstructor and Course.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
   WHERE object_id = OBJECT_ID(N'[dbo].[FK_CourseInstructor_Course]')
   AND parent_object_id = OBJECT_ID(N'[dbo].[CourseInstructor]'))
ALTER TABLE [dbo].[CourseInstructor]  WITH CHECK ADD  
   CONSTRAINT [FK_CourseInstructor_Course] FOREIGN KEY([CourseID])
REFERENCES [dbo].[Course] ([CourseID])
GO
ALTER TABLE [dbo].[CourseInstructor] CHECK 
   CONSTRAINT [FK_CourseInstructor_Course]
GO

-- Define the relationship between CourseInstructor and Person.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
   WHERE object_id = OBJECT_ID(N'[dbo].[FK_CourseInstructor_Person]')
   AND parent_object_id = OBJECT_ID(N'[dbo].[CourseInstructor]'))
ALTER TABLE [dbo].[CourseInstructor]  WITH CHECK ADD  
   CONSTRAINT [FK_CourseInstructor_Person] FOREIGN KEY([PersonID])
REFERENCES [dbo].[Person] ([PersonID])
GO
ALTER TABLE [dbo].[CourseInstructor] CHECK 
   CONSTRAINT [FK_CourseInstructor_Person]
GO

-- Define the relationship between Course and Department.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
       WHERE object_id = OBJECT_ID(N'[dbo].[FK_Course_Department]')
       AND parent_object_id = OBJECT_ID(N'[dbo].[Course]'))
ALTER TABLE [dbo].[Course]  WITH CHECK ADD  
       CONSTRAINT [FK_Course_Department] FOREIGN KEY([DepartmentID])
REFERENCES [dbo].[Department] ([DepartmentID])
GO
ALTER TABLE [dbo].[Course] CHECK CONSTRAINT [FK_Course_Department]
GO

--Define the relationship between OfficeAssignment and Person.
IF NOT EXISTS (SELECT * FROM sys.foreign_keys 
   WHERE object_id = OBJECT_ID(N'[dbo].[FK_OfficeAssignment_Person]')
   AND parent_object_id = OBJECT_ID(N'[dbo].[OfficeAssignment]'))
ALTER TABLE [dbo].[OfficeAssignment]  WITH CHECK ADD  
   CONSTRAINT [FK_OfficeAssignment_Person] FOREIGN KEY([InstructorID])
REFERENCES [dbo].[Person] ([PersonID])
GO
ALTER TABLE [dbo].[OfficeAssignment] CHECK 
   CONSTRAINT [FK_OfficeAssignment_Person]
GO

-- Create InsertOfficeAssignment stored procedure.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[InsertOfficeAssignment]') 
        AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[InsertOfficeAssignment]
        @InstructorID int,
        @Location nvarchar(50)
        AS
        INSERT INTO dbo.OfficeAssignment (InstructorID, Location)
        VALUES (@InstructorID, @Location);
        IF @@ROWCOUNT > 0
        BEGIN
            SELECT [Timestamp] FROM OfficeAssignment 
                WHERE InstructorID=@InstructorID;
        END
' 
END
GO

--Create the UpdateOfficeAssignment stored procedure.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[UpdateOfficeAssignment]') 
        AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[UpdateOfficeAssignment]
        @InstructorID int,
        @Location nvarchar(50),
        @OrigTimestamp timestamp
        AS
        UPDATE OfficeAssignment SET Location=@Location 
        WHERE InstructorID=@InstructorID AND [Timestamp]=@OrigTimestamp;
        IF @@ROWCOUNT > 0
        BEGIN
            SELECT [Timestamp] FROM OfficeAssignment 
                WHERE InstructorID=@InstructorID;
        END
' 
END
GO

-- Create the DeleteOfficeAssignment stored procedure.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[DeleteOfficeAssignment]') 
        AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[DeleteOfficeAssignment]
        @InstructorID int
        AS
        DELETE FROM OfficeAssignment
        WHERE InstructorID=@InstructorID;
' 
END
GO

-- Create the DeletePerson stored procedure.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[DeletePerson]') 
        AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[DeletePerson]
        @PersonID int
        AS
        DELETE FROM Person WHERE PersonID = @PersonID;
' 
END
GO

-- Create the UpdatePerson stored procedure.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[UpdatePerson]') 
        AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[UpdatePerson]
        @PersonID int,
        @LastName nvarchar(50),
        @FirstName nvarchar(50),
        @HireDate datetime,
        @EnrollmentDate datetime
        AS
        UPDATE Person SET LastName=@LastName, 
                FirstName=@FirstName,
                HireDate=@HireDate,
                EnrollmentDate=@EnrollmentDate
        WHERE PersonID=@PersonID;
' 
END
GO

-- Create the InsertPerson stored procedure.
IF NOT EXISTS (SELECT * FROM sys.objects 
        WHERE object_id = OBJECT_ID(N'[dbo].[InsertPerson]') 
        AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[InsertPerson]
        @LastName nvarchar(50),
        @FirstName nvarchar(50),
        @HireDate datetime,
        @EnrollmentDate datetime
        AS
        INSERT INTO dbo.Person (LastName, 
                    FirstName, 
                    HireDate, 
                    EnrollmentDate)
        VALUES (@LastName, 
            @FirstName, 
            @HireDate, 
            @EnrollmentDate);
        SELECT SCOPE_IDENTITY() as NewPersonID;
' 
END
GO

-- Create GetStudentGrades stored procedure.
IF NOT EXISTS (SELECT * FROM sys.objects 
            WHERE object_id = OBJECT_ID(N'[dbo].[GetStudentGrades]') 
            AND type in (N'P', N'PC'))
BEGIN
EXEC dbo.sp_executesql @statement = N'
CREATE PROCEDURE [dbo].[GetStudentGrades]
            @StudentID int
            AS
            SELECT EnrollmentID, Grade, CourseID, StudentID FROM dbo.StudentGrade
            WHERE StudentID = @StudentID
' 
END
GO

-- Insert data into the Person table.
USE School
GO
SET IDENTITY_INSERT dbo.Person ON
GO
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (1, 'Abercrombie', 'Kim', '1995-03-11', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (2, 'Barzdukas', 'Gytis', null, '2005-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (3, 'Justice', 'Peggy', null, '2001-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (4, 'Fakhouri', 'Fadi', '2002-08-06', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (5, 'Harui', 'Roger', '1998-07-01', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (6, 'Li', 'Yan', null, '2002-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (7, 'Norman', 'Laura', null, '2003-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (8, 'Olivotto', 'Nino', null, '2005-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (9, 'Tang', 'Wayne', null, '2005-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (10, 'Alonso', 'Meredith', null, '2002-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (11, 'Lopez', 'Sophia', null, '2004-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (12, 'Browning', 'Meredith', null, '2000-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (13, 'Anand', 'Arturo', null, '2003-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (14, 'Walker', 'Alexandra', null, '2000-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (15, 'Powell', 'Carson', null, '2004-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (16, 'Jai', 'Damien', null, '2001-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (17, 'Carlson', 'Robyn', null, '2005-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (18, 'Zheng', 'Roger', '2004-02-12', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (19, 'Bryant', 'Carson', null, '2001-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (20, 'Suarez', 'Robyn', null, '2004-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (21, 'Holt', 'Roger', null, '2004-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (22, 'Alexander', 'Carson', null, '2005-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (23, 'Morgan', 'Isaiah', null, '2001-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (24, 'Martin', 'Randall', null, '2005-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (25, 'Kapoor', 'Candace', '2001-01-15', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (26, 'Rogers', 'Cody', null, '2002-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (27, 'Serrano', 'Stacy', '1999-06-01', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (28, 'White', 'Anthony', null, '2001-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (29, 'Griffin', 'Rachel', null, '2004-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (30, 'Shan', 'Alicia', null, '2003-09-01');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (31, 'Stewart', 'Jasmine', '1997-10-12', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (32, 'Xu', 'Kristen', '2001-7-23', null);
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (33, 'Gao', 'Erica', null, '2003-01-30');
INSERT INTO dbo.Person (PersonID, LastName, FirstName, HireDate, EnrollmentDate)
VALUES (34, 'Van Houten', 'Roger', '2000-12-07', null);
GO
SET IDENTITY_INSERT dbo.Person OFF
GO

-- Insert data into the Department table.
INSERT INTO dbo.Department (DepartmentID, [Name], Budget, StartDate, Administrator)
VALUES (1, 'Engineering', 350000.00, '2007-09-01', 2);
INSERT INTO dbo.Department (DepartmentID, [Name], Budget, StartDate, Administrator)
VALUES (2, 'English', 120000.00, '2007-09-01', 6);
INSERT INTO dbo.Department (DepartmentID, [Name], Budget, StartDate, Administrator)
VALUES (4, 'Economics', 200000.00, '2007-09-01', 4);
INSERT INTO dbo.Department (DepartmentID, [Name], Budget, StartDate, Administrator)
VALUES (7, 'Mathematics', 250000.00, '2007-09-01', 3);
GO


-- Insert data into the Course table.
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (1050, 'Chemistry', 4, 1);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (1061, 'Physics', 4, 1);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (1045, 'Calculus', 4, 7);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (2030, 'Poetry', 2, 2);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (2021, 'Composition', 3, 2);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (2042, 'Literature', 4, 2);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (4022, 'Microeconomics', 3, 4);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (4041, 'Macroeconomics', 3, 4);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (4061, 'Quantitative', 2, 4);
INSERT INTO dbo.Course (CourseID, Title, Credits, DepartmentID)
VALUES (3141, 'Trigonometry', 4, 7);
GO

-- Insert data into the OnlineCourse table.
INSERT INTO dbo.OnlineCourse (CourseID, URL)
VALUES (2030, 'http://www.fineartschool.net/Poetry');
INSERT INTO dbo.OnlineCourse (CourseID, URL)
VALUES (2021, 'http://www.fineartschool.net/Composition');
INSERT INTO dbo.OnlineCourse (CourseID, URL)
VALUES (4041, 'http://www.fineartschool.net/Macroeconomics');
INSERT INTO dbo.OnlineCourse (CourseID, URL)
VALUES (3141, 'http://www.fineartschool.net/Trigonometry');

--Insert data into OnsiteCourse table.
INSERT INTO dbo.OnsiteCourse (CourseID, Location, Days, [Time])
VALUES (1050, '123 Smith', 'MTWH', '11:30');
INSERT INTO dbo.OnsiteCourse (CourseID, Location, Days, [Time])
VALUES (1061, '234 Smith', 'TWHF', '13:15');
INSERT INTO dbo.OnsiteCourse (CourseID, Location, Days, [Time])
VALUES (1045, '121 Smith','MWHF', '15:30');
INSERT INTO dbo.OnsiteCourse (CourseID, Location, Days, [Time])
VALUES (4061, '22 Williams', 'TH', '11:15');
INSERT INTO dbo.OnsiteCourse (CourseID, Location, Days, [Time])
VALUES (2042, '225 Adams', 'MTWH', '11:00');
INSERT INTO dbo.OnsiteCourse (CourseID, Location, Days, [Time])
VALUES (4022, '23 Williams', 'MWF', '9:00');

-- Insert data into the CourseInstructor table.
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (1050, 1);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (1061, 31);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (1045, 5);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (2030, 4);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (2021, 27);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (2042, 25);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (4022, 18);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (4041, 32);
INSERT INTO dbo.CourseInstructor(CourseID, PersonID)
VALUES (4061, 34);
GO

--Insert data into the OfficeAssignment table.
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (1, '17 Smith');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (4, '29 Adams');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (5, '37 Williams');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (18, '143 Smith');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (25, '57 Adams');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (27, '271 Williams');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (31, '131 Smith');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (32, '203 Williams');
INSERT INTO dbo.OfficeAssignment(InstructorID, Location)
VALUES (34, '213 Smith');

-- Insert data into the StudentGrade table.
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2021, 2, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2030, 2, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2021, 3, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2030, 3, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2021, 6, 2.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2042, 6, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2021, 7, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2042, 7, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2021, 8, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (2042, 8, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4041, 9, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4041, 10, null);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4041, 11, 2.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4041, 12, null);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4061, 12, null);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 14, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 13, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4061, 13, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4041, 14, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 15, 2.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 16, 2);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 17, null);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 19, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4061, 20, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4061, 21, 2);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 22, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4041, 22, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4061, 22, 2.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (4022, 23, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1045, 23, 1.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1061, 24, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1061, 25, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1050, 26, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1061, 26, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1061, 27, 3);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1045, 28, 2.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1050, 28, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1061, 29, 4);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1050, 30, 3.5);
INSERT INTO dbo.StudentGrade (CourseID, StudentID, Grade)
VALUES (1061, 30, 4);
GO

数据库的架构关系图如下：

建好数据库后，我们就可以开始在项目中创建该数据库的实体模型了。

步骤如下：

1.打开VS2010，新建项目（项目类型随便你选择，我这里选择创建MVC3项目并使用Razor模板）

2.在项目的Models文件夹下添加新项，在选择新项模板对话框中选择“ADO.NET实体数据模型”，将该项名字命名为School。

3.上一步点确定之后就会打开“实体数据模型向导”，这里选择“从数据库生成”，点击下一步。

4.在“选择您的数据库连接”中新建连接。在弹出的连接属性里面输入你的数据库服务器和登陆密码，以及选择好你要连接的数据库。然后在“选择您的数据库连接”对话框中将复选框的钩打上。如图：

5.在“选择数据库对象”对话框中展开表，选中你要的表（存储过程之后介绍），然后将“确定所生成对象名称的单复数形式”打勾。如图：

6.点击完成之后，VS会自动打开该实体模型的设计器窗体。School数据库所对应的实体模型就构建好了，如图所示：

从这个图来看，非常像在SysBase PowerDesigner中绘制的ConceptualDataModel。描述了实体之间的关系（E-R）图。

School实体模型创建好了之后生成了一个School.edmx文件，还有一个是School.Designer.cs文件。

edmx文件直接双击打开会启用设计器打开的，这里我们想要查看其具体内容的话，可以使用XML编辑器来打开该文件。该文件中的内容分为两大部分：一部分是edmx：Runtime，实体的运行时；一部分是Designer用于设计器呈现界面效果用的。代码如下图所示：

在Runtime部分的代码有明确的标明分别是SSDL（存储架构定义语言）、CSDL（概念架构定义语言)、C-S mapping(映射规范使用映射规范语言 (MSL))。此部分的代码不细看了，如果有兴趣的可以查看以下MSDN的具体说明。

Designer.cs打开之后分为两个部分代码：一部分是实体上下文；另一部分是实体类。

SchoolEntities这个类就是实体上下文，该类继承自ObjectContext，该类提供一些用于查询和使用对象形式的实体数据的功能。

该类提供三个构造函数重载，可以带数据库的连接字符串，或者实体连接对象，或者什么都不填用默认的连接。

属性部分就是对应每个实体的ObjectSet集合对象。

此外该类还提供一系列的AddTo方法来讲某实体添加到实体模型中。但是在文档中看到一句注释，说该方法已经弃用！改用关联的ObjectSet的add方法。

Designer.cs文件中的代码除了SchoolEntities实体对象外，还有一部分就是实体类。这些类都是继承自EntityObject类来的。

每个继承自EntityObject的类都有一个工厂方法来构建新的自身对象。

其实这个对象就是对应数据库中的一个表，并且基元属性对应这个表中的字段。

另外还有一些导航属性，导航属性就是描述数物理模型中各个表之间的关系的。将来可以通过这个导航属性来访问到相关联的数据。非常实用方便。

该部分的代码非常多，并且也不是很复杂，这里就不详细的列出来说明了。有兴趣的可以自己查看。

查看全文

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原文地址：https://www.cnblogs.com/stevenhqq/p/1985077.html

AOD.NET Entity Framework 实体框架 学习（2 模型和映射）

AOD.NET Entity Framework 实体框架学习（2 模型和映射）