在 mongodb 的文档中查找子元素

Question

我正在处理以下文档

{
"_id" : 123344223,
"firstName" : "gopal",
"gopal" : [ 
    {
        "uuid" : "123",
        "name" : "sugun",
        "sudeep" : [ 
            {
                "uuid" : "add32",
                "name" : "ssss"
            }, 
            {
                "uuid" : "fdg456",
                "name" : "gfg"
            }
        ]
    }, 
    {
        "uuid" : "222",
        "name" : "kiran"
    }
]
}

我想得到如下输出

{
"_id" : 456,
"gopal" : [ 
    {
        "uuid" : "123",
        "name" : "sugun",
        "sudeep" : [ 
            {
                "uuid" : "add32",
                "name" : "ssss"
            }
        ]
    }
]
}

我尝试了很多东西，比如

db.People.findOne({_id:123},{gopal:{$elemMatch:{uuid:"123",sudeep:{$elemMatch:{uuid:"add32"}}}}});

但无论我怎么尝试，returns 文件都是这样的

{
"_id" : 123,
"gopal" : [ 
    {
        "uuid" : "123",
        "name" : "sugun",
        "sudeep" : [ 
            {
                "uuid" : "add32",
                "name" : "ssss"
            }, 
            {
                "uuid" : "fdg456",
                "name" : "gfg"
            }
        ]
    }
]
}

你能帮忙吗？

Answer 1

你知道MongoDBaggregation pipeline吗？

> db.people.aggregate([
    {$match: {_id: 123}}, 
    {$unwind: "$gopal"}, 
    {$unwind: "$gopal.sudeep"}, 
    {$match: {"gopal.uuid": "123", "gopal.sudeep.uuid" : "add32"}}
 ])

输出

{
        "_id" : 123,
        "firstName" : "gopal",
        "gopal" : {
                "uuid" : "123",
                "name" : "sugun",
                "sudeep" : {
                        "uuid" : "add32",
                        "name" : "ssss"
                }
        }
}

Answer 2

在聚合管道中使用 $unwind

db.People.aggregate([{$match:{_id:'123'}},{$match:{gopal.uuid:'123'}},{$unwind:'$sudeep' },{$匹配:{uuid:'add32'}}])

在 mongodb 的文档中查找子元素

Finding subelements in a document in mongodb

mongodb

mongodb-query

aggregation-framework