需要有关 mongo 聚合查询的帮助

如何解决需要有关 mongo 聚合查询的帮助

以下是示例数据：

[{
        "outdoor": {
            "location": {
                "type": "Point","coordinates": [
                    -92.41151,35.11683
                ]
            }
        },"geoHash": "dr72jwgnbbst","status":"Active","customerId":"8047380094","locationId":"A0"

    },{
        "outdoor": {
            "location": {
                "type": "Point","coordinates": [
                    -89.58342,36.859161
                ]
            }
        },"geoHash": "dn6qtkr5xk8m","status":"Pending","locationId":"A1"
    },{
        "outdoor": {

            "location": {
                "type": "Point","coordinates": [
                    -86.038762,36.519016
                ]
            }
        },"geoHash": "dn6zf0h6xtcp","locationId":"A2"
    },"coordinates": [
                    -98.3081936,26.2143207
                ]
            }
        },"geoHash": "9udj4unjmp9f","locationId":"A3"
    },"coordinates": [
                    -98.5377275,29.4878928
                ]
            }
        },"geoHash": "9v1zv8p52t8u","locationId":"A4"
    },"coordinates": [
                    -73.7018126,42.641387
                ]
            }
        },"geoHash": "dreddfeup69m","locationId":"A5"
    },"coordinates": [
                    -111.865295,33.431942
                ]
            }
        },"geoHash": "9tbqnqn5jtwq","locationId":"A6"
    },"coordinates": [
                    -79.810763,34.174603
                ]
            }
        },"geoHash": "dnp4rv796rtz","locationId":"A7"
    }
]

目前我们正在运行 2 个查询：

查询 1 - 此查询将按按 geoHash 子字符串分组的状态提供计数。

db.locations.aggregate([{"$match": {"customerId": "8047380094"}},{"$project": {"status": 1,"geoHash": {"$substr": ["$geoHash",2]}}},{"$group": {"_id": {"geoHash": "$geoHash","status": "$status"},"statusCount": {"$sum": 1}}}],{
  "allowdiskUse": true
});

输出 1：

{ "_id" : { "geoHash" : "dr","status" : "Active" },"statusCount" : 1 }
{ "_id" : { "geoHash" : "dr","status" : "Pending" },"statusCount" : 1 }
{ "_id" : { "geoHash" : "dn","statusCount" : 2 }
{ "_id" : { "geoHash" : "dn","statusCount" : 1 }
{ "_id" : { "geoHash" : "9u","statusCount" : 1 }
{ "_id" : { "geoHash" : "9v","statusCount" : 1 }
{ "_id" : { "geoHash" : "9t","statusCount" : 1 }

查询 2 - 我们有一个查询来获取 geohash 组的第一个位置坐标。

db.locations.aggregate([{"$match": {"customerId": "8047380094"}},{"$project": {"geoHash": {"$substr": ["$geoHash",2]},"locations": "$outdoor.location.coordinates"}},{"$group": {"_id": "$geoHash","locations": {"$push": "$locations"}}},{"$project": {"_id": 1,"locations": {"$arrayElemAt": ["$locations",0]}}}],{
  "allowdiskUse": true
});

输出 2：

{ "_id" : "dr","locations" : [ -92.41151,35.11683 ] }
{ "_id" : "dn","locations" : [ -89.58342,36.859161 ] }
{ "_id" : "9u","locations" : [ -98.3081936,26.2143207 ] }
{ "_id" : "9v","locations" : [ -98.5377275,29.4878928 ] }
{ "_id" : "9t","locations" : [ -111.865295,33.431942 ] }

问题 1： 是否可以将两个查询合并为 1 并在单个查询中获得两个输出？

问题 2： 如果总计数为 1（不是按状态），我们还需要获取 locationId 吗？我们如何在同一个查询中实现这一点？ 在上述情况下， 对于“9u”，我们需要返回 A3 对于“9v”，我们需要返回 A4 对于“9t”，我们需要返回 A6

注意：我们在 spring mongo 中使用 spring boot 应用程序。

解决方法

我没有按照您尝试实现的目标进行操作，因为问题没有提及它。但是对于你们两个问题，我都可以回答

1. 您可以使用 $facet 创建多个聚合管道
2. 通过使用第一个 $facet 阶段，您可以使用额外的阶段来获取您的 locationId；

这是代码

{
    $project: {
      firstQuery: 1,secondQuery: {
        $map: {
          input: "$secondQuery",as: "s",in: {
            $mergeObjects: [
              "$$s",{
                $arrayElemAt: [
                  {
                    $map: {
                      input: {
                        $filter: {
                          input: "$firstQuery",as: "f",cond: { $eq: ["$$f._id.geoHash","$$s._id" ] }
                        }
                      },in: { locationId: "$$this.locationId" }
                    }
                  },0
                ]
              }
            ]
          }
        }
      }
    }
  }

工作Mongo playground

注意：确保 { $eq: ["$$f._id.geoHash","$$s._id" ] } 将给出一个独特的对象。否则需要另一个想法。而且我觉得您发布的两个查询更像是相同的。所以可以有一个简单的解决方案。但我是根据你发布的问题回答的