Question

我创建了一种方法，通过实体框架将数据从数据表添加到数据库中的表中，但是它只允许我填充一个表，并且我想在一个方法中填充多个表。

下面是我添加到学生表的方法，我已经注释掉了模块表，因为当我添加它时，没有数据被传输到数据库。有人可以推荐一种方法，我可以在这个方法中填充多个表吗？

由于

public Boolean ConvertDataTable(DataTable tbl)
    {
        string Feedback = string.Empty;
        ModuleEntities db = new ModuleEntities();
        // iterate over your data table
        foreach (DataRow row in tbl.Rows)
        {

            student st = new student();
            st.student_no = row.ItemArray.GetValue(0).ToString();
            st.surname = row.ItemArray.GetValue(1).ToString();
            st.firstname = row.ItemArray.GetValue(2).ToString();
            db.students.Add(st);
            //module mod = new module();
            //mod.module_code = row.ItemArray.GetValue(3).ToString();
            //mod.name = row.ItemArray.GetValue(4).ToString();
            //db.modules.Add(mod);


        }
        try
        {
            db.SaveChanges();
            Feedback = "Upload Successful";
            return true;
        }
        catch
        {
            Feedback = "Upload Failed";
            return false;
        }

    }

学生班

public partial class student
{
    public student()
    {
        this.submits = new HashSet<submit>();
        this.takes = new HashSet<take>();
        this.lecturers = new HashSet<lecturer>();
    }

    public string student_no { get; set; }
    public string surname { get; set; }
    public string firstname { get; set; }

    public virtual ICollection<submit> submits { get; set; }
    public virtual ICollection<take> takes { get; set; }
    public virtual ICollection<lecturer> lecturers { get; set; }
}

模块类

public partial class module
{
    public module()
    {
        this.takes = new HashSet<take>();
        this.lecturers = new HashSet<lecturer>();
    }

    public string module_code { get; set; }
    public string name { get; set; }

    public virtual ICollection<take> takes { get; set; }
    public virtual ICollection<lecturer> lecturers { get; set; }
}

上课

public partial class take
{
    public string student_no { get; set; }
    public string module_code { get; set; }
    public string grade { get; set; }

    public virtual module module { get; set; }
    public virtual student student { get; set; }
}

Answer 1

以下是使用Entity Framework将相关数据添加到数据库的要点：

class Program
{
    static void Main(string[] args)
    {
        SchoolDBEntities dataContext = new SchoolDBEntities();
        //Create student object
        Student student1 = new Student();
        student1.StudentName = "Student 01";
        //Create course objects
        Cours mathCourse = new Cours();
        mathCourse.CourseName = "Math";
        Cours scienceCourse = new Cours();
        scienceCourse.CourseName = "Science";
        //Save courses to student 1
        student1.Courses.Add(mathCourse);
        student1.Courses.Add(scienceCourse);
        //Save related data to database
        //This will automatically populate join table
        //between Students and Courses
        dataContext.Students.Add(student1);
        dataContext.SaveChanges();
    }
}

另一个例子：

在实体框架中将数据表更新为多个表

1 个答案: