Entity Framework Core 中没有嵌套结果 [英] No nested results in Entity Framework Core

问题描述

我在 C# 中使用 EF 有一个奇怪的行为这是一个带有 EF Core 1.1.0 的 .NET Core 项目

i have a strange behavior in C# with EF It's a .NET Core project with EF Core 1.1.0

"Microsoft.EntityFrameworkCore.SqlServer": "1.1.0",
"Microsoft.EntityFrameworkCore.Tools": "1.1.0-preview4-final",

我创建了两个模型，用户"和组"

I've created two Models, "User" and "Group"

 public class User
 {
    public int Id { get; set; }
    public string name { get; set; }
    public string lastName { get; set; }

    public List<Group> Groups { get; set; }
 }

 public class Group
 {
    public int Id { get; set; }
    public string groupName { get; set; }
    public virtual User User { get; set; }
 }

结果应该给我一个包含他的组列表的用户.

The result schould give me a User with a list of his groups.

现在是奇怪的部分:

结果从数据库返回，我查看所有用户，组为空

Result comes back from DB, i look into allUser, Groups are Null

我查看上下文以查看组

组已满:

现在我再次查看 allUser Result 并且神奇地该组填充在每个用户项中.

Now i look again into allUser Result and magically the Group is filled inside every User item.

组在用户内部填充:

我非常感谢您的帮助！！

I really appreciate any help!!

推荐答案

看起来您在延迟加载实体.

Looks like you are lazy loading the entities.

您可以使用 .Include 预先加载它们.

You can eager load them by using .Include.

 var allUsers = context.Users.Include(user => user.Groups).ToList();

此方法加载第一个实体(用户)以及相关实体作为查询(组)的一部分.

This approach loads the first entity (Users) as well as the related entities as part of the query (Groups).

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