的LINQ到SQL添加方法

Question

讓我們假設我們有這個表

CREATE TABLE dbo.Students 
(
    StudentID INT IDENTITY(1,1) PRIMARY KEY, 
    Name varchar(50) 
); 

CREATE TABLE dbo.StudentLoans 
(
    LoanID INT IDENTITY(1,1) PRIMARY KEY, 
    StudentID INT FOREIGN KEY REFERENCES dbo.Students(StudentID), 
    Amount int 
); 

，我們在表單代碼

using(var myContextInstance=new YourContext()) 
{ 
    var student = new Student(){Name = "user962206"}; 
    var studentLoan = new StudentLoan(){Amount = 50000}; 
    student.StudentLoans.Add(studentLoan); 
    myContextInstance.Students.InsertOnSubmit(student); 
    myContextInstance.SubmitChanges(); 
} 

下面的代碼並允許進一步假設，我拖放棄我的表進我的O/R設計師，同時我有一類LINQ to SQL classes

每行代碼在這裏做什麼？特別是

student.StudentLoans.Add(studentLoan); 

.Add（studentLoan）方法具體做什麼？

Answer 1

它會在StudentLoans表中插入一個新條目。這個新條目的StudentId將具有新添加的學生的價值。

編輯

另一種方式

using(var myContextInstance=new YourContext()) 
{ 
    // create a new student instance 
    var student = new Student(){Name = "user962206"}; 
    // inserts this student by calling SubmitChanges; student.StudentID will have new value from database 
    myContextInstance.Students.InsertOnSubmit(student); 
    myContextInstance.SubmitChanges(); 

    // create a new student load object 
    var studentLoan = new StudentLoan(){Amount = 50000}; 
    // assign the StudentID 
    studentLoan.StudentID = student.StudentID; 
    // you can assign the student via the Student property also 
    // or studentLoan.Student = student; 

    // save the new StudentLoan object into the database 
    myContextInstance.StudentLoans.InsertOnSubmit(studentLoan); 
    myContextInstance.SubmitChanges(); 
}