如何在mongoDB中使用通配符字段?

时间:2018-11-27 14:06:12

标签: mongodb mongodb-query aggregation-framework

任何人都可以帮助我提取包含“ Australia”作为国家/地区的记录,而我们不知道Mongo Query中日期图中的键(日期)。

我的样本数据....

`{
    "_id" : ObjectId("5bfbdf1f123ee9f1b2bb82e0"),
    "fruit" : "apple",
    "datemap" : {
        "11/26/2018" : [ 
            {
                "_id" : "bbc2bb53-b7fe-43ec-9e88-38efbd69c345",
                "country" : "Denmark"
            }
        ],
            "11/27/2018" : [ 
            {
                "_id" : "bbc2bb53-b7fe-43ec-9e88-38efbd68c345",
                "country" : "Norway"
            }
        ],
            "11/28/2018" : [ 
            {
                "_id" : "bbc2bb54-b7fe-43ec-9e88-38efbd68c345",
                "country" : "Australia"
            }
        ]
    }
},
{
    "_id" : ObjectId("5bfbdf1f123ee9f1b2bb8245"),
    "fruit" : "Orange",
    "datemap" : {
        "11/26/2018" : [ 
            {
                "_id" : "bbc2bb53-b7fe-43ec-9e88-38efbd69c345",
                "country" : "Brazil"
            }
        ],
            "11/29/2018" : [ 
            {
                "_id" : "bbc2bb53-b7fe-43ec-9e88-38efbd68c345",
                "country" : "England"
            }
        ],
            "11/30/2018" : [ 
            {
                "_id" : "bbc2bb54-b7fe-43ec-9e88-38efbd68c345",
                "country" : "Australia"
            }
        ]
    }
}`

提前谢谢。...

1 个答案:

答案 0 :(得分:3)

您可以使用$objectToArray将未知密钥转换成k v对,然后设置$match条件。

类似

db.collection.aggregate([
  { "$addFields": { "country": { "$objectToArray": "$datemap" } } },
  { "$match": { "country.v.country": "Australia" } },
  { "$project": { "country": 0 }}
])
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