使用带有$lookup和$match的聚合搜索查询mongodb

我正在为一个我不知道有多真实的问题而挣扎。。。我假装做一个搜索输入，在那里我想找到一个客户，并从这个客户那里获得我需要的所有信息。 我有三个收藏

客户集合

费率收集

配置集合

我正在执行的查询是。。。（我只从我的应用程序中收到searchTerm）

但是这个查询不起作用，它说$rate没有定义。。。我想我不知道它到底是怎么工作的，我怎么能申报美元汇率呢？我认为如果cliente.rate是clientModel的一个属性，那么它的定义是。。。请帮助

您可以尝试以下操作：

db.clienteModel.aggregate([
    {
        $match: { 
                $or: [                   
                    { name: { '$regex': req.body.searchTerm, '$options': 'i' } },
                ]
            }       
    },
    {
        $lookup: {
            from: "rate",
            let: { "rateId": "$rate" },
            pipeline: [
                {
                    $match: {
                        $expr: { $eq: ["$_id", "$$rateId"] },
                    }
                }
            ],
            as: "rateDetails"
        }
    },
    {
        $lookup: {
            from: "config",
            let: { "rateId": "$rate" },
            pipeline: [
                {
                    $match: {
                        $expr: { $eq: ["$idRate", "$$rateId"] },
                    }
                }
            ],
            as: "configDetails"
        }
    },
]);

输出：

{
    "_id" : ObjectId("5e7fb25ddc976375d3c224eb"),
    "name" : "Jhon",
    "rate" : ObjectId("5e7fb22fdc976375d3c224ea"),
    "rateDetails" : [
        {
            "_id" : ObjectId("5e7fb22fdc976375d3c224ea"),
            "title" : "Rate for sellers",
            "margin" : 10
        }
    ],
    "configDetails" : [
        {
            "_id" : ObjectId("5e7fb2a2dc976375d3c224ec"),
            "idRate" : ObjectId("5e7fb22fdc976375d3c224ea"),
            "maring" : 8
        }
    ]
}

---

非常感谢，你成功了！我必须学习更多关于聚合的知识，我想我缺少了一些概念。。。就像“让”来定义。。。再次感谢！

{
    _id: '5e7276249110c43528f21402'
    idRate: '5e790595b0d727313cb56d3b'
    maring: 8,
}

clienteModel.aggregate([
        //in the first stage i find the client by searchTerm that contains the Name;
        {
            $match: { 
                $or: [                   
                    { name: { '$regex': req.body.searchTerm, '$options': 'i' } },
                ]
            }
        },
        //in the second stage i would like to receive only the Rate that match with the client.rate
        {
            $lookup: {
               from: "rates",
                as: "rate",
                pipeline: [
                   {
                       $match: {
                        _id: $rate
                       }
                   }
               ]
           }
      }
        //in the third stage, i would like to bring the configs that match with client.rate
        {
            $lookup: {
                from: "configs",
                as: "config",
                pipeline: [
                    {
                        $match: {
                            idRate: $rate
                        }
                    }
                ]
            }
        }

    ])

db.clienteModel.aggregate([
    {
        $match: { 
                $or: [                   
                    { name: { '$regex': req.body.searchTerm, '$options': 'i' } },
                ]
            }       
    },
    {
        $lookup: {
            from: "rate",
            let: { "rateId": "$rate" },
            pipeline: [
                {
                    $match: {
                        $expr: { $eq: ["$_id", "$$rateId"] },
                    }
                }
            ],
            as: "rateDetails"
        }
    },
    {
        $lookup: {
            from: "config",
            let: { "rateId": "$rate" },
            pipeline: [
                {
                    $match: {
                        $expr: { $eq: ["$idRate", "$$rateId"] },
                    }
                }
            ],
            as: "configDetails"
        }
    },
]);

{
    "_id" : ObjectId("5e7fb25ddc976375d3c224eb"),
    "name" : "Jhon",
    "rate" : ObjectId("5e7fb22fdc976375d3c224ea"),
    "rateDetails" : [
        {
            "_id" : ObjectId("5e7fb22fdc976375d3c224ea"),
            "title" : "Rate for sellers",
            "margin" : 10
        }
    ],
    "configDetails" : [
        {
            "_id" : ObjectId("5e7fb2a2dc976375d3c224ec"),
            "idRate" : ObjectId("5e7fb22fdc976375d3c224ea"),
            "maring" : 8
        }
    ]
}