Question

我有两个实体类定义为

1）项目类

public class Project
{
     [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int ProjectId { get; set; }  
    public string Title { get; set; }
    public string Description { get; set; }
    public DateTime CreatedDate { get; set; }
    public ICollection<Person> Persons { get; set; }
}

2）人员类

    public class Person
    {
        public Person()
        {
            Projects = new List<Project>();
        }


        [Key]
        [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
        public int PersonId { get; set; }
        public string Name { get; set; }
        public string EmailAddress { get; set; }
        public string Designation { get; set; }
        public string CellPhone { get; set; }
        public ICollection<Project> Projects { get; set; }
    }

在我的DataContext类中，配置定义为

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

        public DbSet<Project> Projects { get; set; }

        public DbSet<Person> Persons { get; set; }


        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Project>()
               .HasMany<Person>(p => p.Persons)
               .WithMany(p => p.Projects)
               .Map(m =>
               {
                   m.ToTable("ProjectPersons");
                   m.MapLeftKey("ProjectId");
                   m.MapRightKey("PersonId");
               });


        }

    }

创建新项目后，项目表和Person表填充了它的记录，但我注意到ProjectPerson表是通过加入而不是用ProjectId和PersonId填充的。

有什么建议吗？

这是我创建新项目的HttpPost方法

[HttpPost]
        public ActionResult CreateProject(Projects newProject, int page = 1)
        {


            _ctx.Projects.AddProject(newProject, ref _ctx);
            _ctx.Person.AddPerson(newProject.Person, newProject, ref _ctx);

            _ctx.SaveChanges();

var userProjects = _ctx.Projects.GetStaffUserProjects(providerUserKey, page, ref _ctx);
                    return PartialView("_Projects", userProjects);

        }

这是我的扩展方法'AddProject'和'AddPerson'

1）AddProject

public static void AddProject(this IEnumerable<Project> projects, Projects newProject, ref DataContext ctx)
        {


               var project = new Project
                               {
                                   Title = newProject.Title,
                                   Duration = newProject.Duration,
                                   Description = newProject.Description,
                                   CreatedDate = DateTime.Now,
                                   Status = true,
                                   UserId = (int)Membership.GetUser().ProviderUserKey,
                                   ProjectCategoryId = newProject.SelectedProjectCategoryId,
                                   OrganizationId = newProject.SelectedOrganizationId
                               };




            ctx.Projects.Add(project);
        }

2）AddPerson

public static void AddPerson(this IEnumerable<Person> persons, Person newPerson, Projects newProject, ref DataContext ctx)
        {



                   var person = new Person
                                   {
                                       Name = newPerson.Name,
                                       EmailAddress = newPerson.EmailAddress,
                                       CellPhone = newPerson.CellPhone,
                                       Designation = newPerson.Designation
                                   };



                ctx.Person.Add(person);
            }
        }

Answer 1

要创建人与项目之间的关系，您必须将已添加或附加到上下文的项目添加到相应的导航集合中。要执行此操作（对现有代码进行最少的更改），请从AddProject：

返回创建的项目
public static Project AddProject(this IEnumerable<Project> projects, Projects newProject, ref DataContext ctx) { var project = new Project { ... }; ctx.Projects.Add(project); return project; }

然后将此返回的项目传递到AddPerson：

var project = _ctx.Projects.AddProject(newProject, ref _ctx); _ctx.Person.AddPerson(newProject.Person, project, ref _ctx); _ctx.SaveChanges();

并在AddPerson中将其添加到此人的Projects集合中：

public static void AddPerson(this IEnumerable<Person> persons, Person newPerson, Projects project, ref DataContext ctx) { var person = new Person { ... }; if (project != null) person.Projects.Add(project); // the preceding line tells EF about the relationship and will make it // generate an INSERT statement for the link table ProjectPerson ctx.Person.Add(person); }

如何在Join表中插入使用EF Code First创建的数据

1 个答案: