node js mongoose如何从两个集合中获取记录

Question

在下面的集合中，我想尝试从coin_infos _id coin_infos coin_id wallet_infos user_id _id:objectID(5a4b07b2a0050c20a6be44b3), coin_code:BTC, wallet_name:bitcoin, deposite_txn_fee:3, min_withdrawn:5, withdrawn_txn_fee:0.001, 和 _id:objectID(5a58a4e222068e053d71220d), user_id:5a4b0787a0050c20a6be44b2, coin_id:5a4b07b2a0050c20a6be44b3, balance:3.122858, 获取所有记录}。

coin_infos集合

{

_id:objectID(5a4b07b2a0050c20a6be44b3),
coin_code:BTC,
wallet_balance:3.122858,
wallet_name:bitcoin,
deposite_txn_fee:3,
min_withdrawn:5,
withdrawn_txn_fee:0.001,

"match_records" : [

_id:objectID(5a58a4e222068e053d71220d),
user_id:5a4b0787a0050c20a6be44b2,
coin_id:5a4b07b2a0050c20a6be44b3,
balance:3.122858,
 ] 
} 

wallet_infos集合

{{1}}

我有用户名 - ：5a4b0787a0050c20a6be44b2

输出如下：..

{{1}}

我的mongoDB版本 3.2.11。

Answer 1

您可以使用$lookup和$match聚合管道，就像您已经在mongo版本3.2 +

$lookup将coin_infos集合与wallet_infos coin_id加入，如果找到匹配，则会将钱包信息作为嵌入文档返回，来自嵌入式文档user_id即可执行$match并过滤

db.coin_infos.aggregate(
    [
        {
            $lookup : {
                from : "wallet_infos",
                localField : "_id",
                foreignField: "coin_id",
                as : "walletInfo"
            }
        },
        {$match : {"walletInfo.userId" : "5a4b0787a0050c20a6be44b2"}}
    ]
)