获取在特定字段 mongo 节点上搜索的所有字段

Question

所以我有两个不同的集合，一个是 users，第二个是 product，我想按名称字段搜索产品，它应该提供所有数据users 集合中的用户详细信息。

代码 sn-p：

app.get('/api/searchProduct/:name', function(request, response) {
    search = request.params.name;
    product.aggregate([
        { "$project": { "supplierID": { "$toObjectId": "$supplierID" } } },
        { $lookup: {
            "localField": "supplierID",
            "from": "users",
            "foreignField": "_id",
            "as": "userDetails"
        }},

        ], function(error, data) {
            if(error) {
                return response.send(error);
            } else {
                response.status(200).json({
                    status: 'success',
                    data: data,
                })
                console.log(JSON.stringify(data));
            }
        })
    })

实际 JSON 结果：

{
  "status": "success",
  "data": [
    {
      "_id": "5e89b936e20452a419ccbcad",
      "supplierID": "5e89b916e20452a419ccbcac",
      "userDetails": [

      ]
    },
    {
      "_id": "5e89bc5ee20452a419ccbcb0",
      "supplierID": "5e89bc48e20452a419ccbcae",
      "userDetails": [
        {
          "_id": "5e89bc48e20452a419ccbcae",
          "timestamp": "2020-04-05T10:37:09.582Z",
          "name": "Mohamma Junaid Raza",
          "email": "junaidraza10896@gmail.com",
          "password": "Iamjunaidr@10896",
          "contact": "",
          "userType": "",
          "profilePhoto": "",
          "__v": 0
        }
      ]
    },
    {
      "_id": "5e89c12bf312e7a5cdfe2e9e",
      "supplierID": "5e89bc48e20452a419ccbcae",
      "userDetails": [
        {
          "_id": "5e89bc48e20452a419ccbcae",
          "timestamp": "2020-04-05T10:37:09.582Z",
          "name": "Mohamma Junaid Raza",
          "email": "junaidraza10896@gmail.com",
          "password": "Iamjunaidr@10896",
          "contact": "",
          "userType": "",
          "profilePhoto": "",
          "__v": 0
        }
      ]
    },

  ]
}

我想要产品的完整详细信息（字段），并在产品数据下方显示的名称字段上进行搜索查询：

Answer 1

试试这个代码：

app.get('/api/searchProduct/:name', function(request, response) {
    search = request.params.name;
    product.aggregate([
        {$match : {name : search}},
        { "$addFields": { "supplierID": { "$toObjectId": "$supplierID" } } },
        { $lookup: {
            "localField": "supplierID",
            "from": "users",
            "foreignField": "_id",
            "as": "userDetails"
        }},
        { "$addFields": { "supplierID": { "$toString": "$supplierID" } } }
        ], function(error, data) {
            if(error) {
                return response.send(error);
            } else {
                response.status(200).json({
                    status: 'success',
                    data: data,
                })
                console.log(JSON.stringify(data));
            }
        })
    })

问题：

1. 您将$project 作为第一阶段，这将只为集合中的每个文档留下两个转换为supplierID 和_id 的字段。而是使用$addFields，它将保留文档中的所有字段并将supplierID 的字符串值替换为ObjectId()，反之亦然。
2. 您尚未针对名称与输入匹配的特定文档过滤您的集合，请使用 $match 过滤文档。