使用 EF 查询相关 table 的最佳实践是什么

Question

我有 Asp.Net Core 2 Web Api 应用程序，我正在使用 Ef Core 2 和 Repository / Unit of Work 模式。我必须从 Database 查询用户帖子，帖子实体如下所示：

public class Post
{
    public int Id { get; set; }
    // This is User Id from AspNetUsers
    public string AuthorId { get; set; }

    public string PostContent { get; set; }
}

在我的存储库中我有查询：

public class FeedRepository : BaseRepository, IFeedRepository, IDisposable
{
    public FeedRepository(ApplicationDbContext context) : base(context)
    {
    }

    public IEnumerable<Post> GetPosts(string currentUserId, IEnumerable<string> followingUserIds)
    {
        // Which returns list of Post entities
        return Db.Posts.Where(p => p.AuthorId == currentUserId || followingUserIds.Contains(p.AuthorId));
    }
    ...
}

所以我的意思是我想return这样回应：

[
    {
        "id": "1",
        "authorId": "asdasd-fg4543-fgfvc-45345-sdfsf",
        "authorFullName": "Jane Doe",
        "postContent": "Test Post by Jane Doe.."
    }
]

Join 或以某种方式获取作者全名并放入同一条目的最佳做法是什么？

Answer 1

首先你必须将 Author 属性添加到 Post

public class Post
{
    public int Id { get; set; }
    // This is User Id from AspNetUsers
    public string AuthorId { get; set; }

    public User Author { get; set; }

    public string PostContent { get; set; }
}

表示没有User就不能创建Post。

使用 Include 通过 EF

检索导航属性值

public IEnumerable<Post> GetPosts(string currentUserId, IEnumerable<string> followingUserIds)
{
    return Db.Posts.Include(it => it.Author).Where(p => p.AuthorId == currentUserId || followingUserIds.Contains(p.AuthorId));
}

使用 EF 查询相关 table 的最佳实践是什么

What is the best practice querying related table with EF

c#

asp.net-core-2.0

asp.net-core-webapi

ef-core-2.0