Question

我正在处理以下文件

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

我希望我的输出如下

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

我试过很多像

这样的事情

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

但无论我尝试过什么，都会像这样返回文件

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

你可以帮忙吗？

Answer 1

您是否了解MongoDB aggregation pipeline？

> 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（[{$匹配：{_ ID： '123'}}，{$匹配：{gopal.uuid： '123'}}，{$展开： '$萨迪普'}，{$匹配：{UUID： 'ADD32'}}]）

在mongodb中查找文档中的子元素

2 个答案: