播种多对多数据

您好，我正在尝试为我的项目创建一些种子，但我在将多对多关系数据播种到数据库时遇到问题。

My database看起来像这样：

in 教师技能, 教师ID and Skill_ID当然是他们的表的外键。

My seeder看起来像这样

protected override void Seed(Ability_Examen_ASP.Models.AbilityDbContext context)
    {
        if (!context.Skills.Any())
        {
            context.Skills.Add(new Models.Skill { SkillName = "PHP" });
            context.Skills.Add(new Models.Skill { SkillName = "Java" });
            context.Skills.Add(new Models.Skill { SkillName = "Frans" });
            context.Skills.Add(new Models.Skill { SkillName = "Drupal" });
        }

        if (!context.Teachers.Any())
        {
            context.Teachers.Add(new Models.Teacher
            {
                FirstName = "Joris",
                LastName = "Hens",
                Campus = "Kruidtuin",
                Password = "testpass",
                Email = "Joris.Hens@"
            });
            context.Teachers.Add(new Models.Teacher
            {
                FirstName = "Anne",
                LastName = "Van Goetem",
                Campus = "Kruidtuin",
                Password = "testpass",
                Email = "Anne.Vangoetem@"
            });
            context.Teachers.Add(new Models.Teacher
            {
                FirstName = "Sofie",
                LastName = "Krekels",
                Campus = "De Ham",
                Password = "testpass",
                Email = "Sofie.Krekels@"
            });
            context.Teachers.Add(new Models.Teacher
            {
                FirstName = "Robby",
                LastName = "Vanelderen",
                Campus = "De Vest",
                Password = "testpass",
                Email = "Robby.Vanelderen@"
            });
        }

        if (!context.TeacherSkills.Any())
        {
            context.TeacherSkills.Add(new Models.TeacherSkill
            {
                Teacher_ID = 1,
                Skill_ID = 1,
            });
            context.TeacherSkills.Add(new Models.TeacherSkill
            {
                Teacher_ID = 1,
                Skill_ID = 4,
            });
            context.TeacherSkills.Add(new Models.TeacherSkill
            {
                Teacher_ID = 2,
                Skill_ID = 2,
            });
            context.TeacherSkills.Add(new Models.TeacherSkill
            {
                Teacher_ID = 3,
                Skill_ID = 3,
            });
            context.TeacherSkills.Add(new Models.TeacherSkill
            {
                Teacher_ID = 4,
                Skill_ID = 4,
            });
        }

    }

老师和技能播种没有任何问题，但我无法向老师播种任何技能。

它没有给我任何错误，而且我不确定出了什么问题。

希望大家能够帮忙，谢谢！

添加呼叫至

context.SaveChanges();  

在你填补教师的地方和你将在哪里播种教师技能之间。这应该提交技能和教师集合，以便您对关键列（身份值）的假设将被替换为执行 INSERT 时实际生成的值。

此外，可以在 TeacherSkills 构造函数中检索和使用实际的教师和技能 ID 值，以消除种子代码中的“幻数”1-4。