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我想我會覺得自己像一個白癡，當我找出答案，但我不明白爲什麼EF7不像我習慣的那樣保存對象圖在EF6工作。EF7沒有保存對象圖
我的背景是：
public class BloggingContext : DbContext, IBloggingContext
{
public DbSet<Blog> Blogs { get; set; }
public DbSet<Post> Posts { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
// Make Blog.Url required
modelBuilder.Entity<Blog>()
.Property(b => b.Url)
.Required();
modelBuilder.Entity<Post>()
.Reference(p => p.Blog)
.InverseCollection(b => b.Posts)
.ForeignKey(p => p.BlogId);
}
}
public class Blog
{
private ICollection<Post> _posts;
public int BlogId { get; set; }
public string Url { get; set; }
public virtual ICollection<Post> Posts
{
get
{
if (_posts == null)
{ _posts = new Collection<Post>(); }
return _posts;
}
protected set
{ _posts = value; }
}
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public int BlogId { get; set; }
public Blog Blog { get; set; }
}
然後我寫了下面的代碼：
using (var db = new BloggingContext())
{
var blog = new Blog() { Url = DateTime.Now.ToString() };
blog.Posts.Add(new Post() { Title = "Foo", Content = "Foo" });
blog.Posts.Add(new Post() { Title = "Bar", Content = "Bar" });
db.Blogs.Add(blog);
var count = db.SaveChanges();
Console.WriteLine("{0} records saved to database", count);
return blog.BlogId;
}
SaveChanges之後被稱爲blog對象有一個BlogId，但在這兩個Post對象BlogId仍然是 - 1並沒有任何東西被添加到數據庫中。