修改model，映射到表中

public class MyContext : DbContext
{
    public MyContext()
        : base("name=MyContext")
    {
        Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyContext,MyConfiguration>()); //重要
    }

    public virtual DbSet<Student> Students { get; set; }
    public virtual DbSet<Course> Courses { get; set; }
}
internal sealed class MyConfiguration : DbMigrationsConfiguration<MyContext>
{
    public MyConfiguration()
    {
        AutomaticMigrationsEnabled = true;
        AutomaticMigrationDataLossAllowed = true;
    }

    protected override void Seed(MyContext context)
    {

    }
}