使用MongoDB進行社交網絡查詢

我對MongoDB有一個簡單的社交網絡實現。我的架構看起來像這樣：使用MongoDB進行社交網絡查詢

User 
    _id 
    name 

Friend 
    _id 
    user 
    friend 

Post 
    _id 
    user 
    timestamp 
    text

我試圖使用aggregate方法從我所有的朋友們最近發表的文章列表，但我想從同一個用戶羣一起連續帖子。因此，假設我有3個朋友，他們有以下職位：

{"user": "user1", timestamp: 1476200010, text: "hello1"} 
{"user": "user2", timestamp: 1476200009, text: "hello2"} 
{"user": "user2", timestamp: 1476200008, text: "hello3"} 
{"user": "user3", timestamp: 1476200007, text: "hello4"} 
{"user": "user2", timestamp: 1476200006, text: "hello5"} 
{"user": "user2", timestamp: 1476200005, text: "hello6"} 
{"user": "user1", timestamp: 1476200004, text: "hello7"} 
{"user": "user1", timestamp: 1476200003, text: "hello8"}

我想作爲一個結果，獲得以下信息：

{"user": "user1", timestamp: 1476200010, text: "hello1"} 
{"user": "user2", timestamp: 1476200009, text: "hello2"} 
{"user": "user3", timestamp: 1476200007, text: "hello4"} 
{"user": "user2", timestamp: 1476200006, text: "hello5"} 
{"user": "user1", timestamp: 1476200004, text: "hello7"}

我堅持我的查詢了一下，任何幫助表示讚賞：

db.Post.aggregate([ 
    {$sort: {timestamp: -1}}, 
    {$lookup: {from: 'Friend', localField: '_id', foreignField: 'friend', as: 'friend'}}, 
    {$match: {'friend.user': current_user}}, 
    ??? 
    {$limit: 100}, 
])

來源

2016-10-11 Gilad Novik

關於這個問題，'aggregate'沒有任何支持涉及到鄰居文檔的操作，所以我認爲你需要在你的應用程序代碼中進行連續的post修剪。 – JohnnyHK