Question

如何在多维数组中搜索值，例如，我想在mongodb中的以下数据中搜索example关键字我曾经从命令

中获取所有数据

>db.info.find()

{
    "_id" : ObjectId("4f74737cc3a51043d26f4b90"),
    "id" : "12345",
    "info" : [
            {
                    "sno" : 1,
                    "name" : "ABC",
                    "email" : "abc@example.com"
            },
            {
                    "sno" : 2,
                    "name" : "XYZ",
                    "email" : "xyz@example.com"
            },
            {
                    "sno" : 3,
                    "name" : "XYZ",
                    "email" : "xyz@demo.com"
            },
            {
                    "sno" : 4,
                    "name" : "ABC",
                    "email" : "abc@demo.com"
            },
            {
                    "sno" : 5,
                    "name" : "Rohan",
                    "email" : "rohan@example.com"
            }
    ]
}

现在，要查找具有example的数据，我使用了命令

>db.info.find({"info.email":"example"}) 它给出了

{
    "_id" : ObjectId("4f74737cc3a51043d26f4b90"),
    "id" : "12345",
    "info" : [
            {
                    "sno" : 1,
                    "name" : "ABC",
                    "email" : "abc@example.com"
            },
            {
                    "sno" : 2,
                    "name" : "XYZ",
                    "email" : "xyz@example.com"
            },
            {
                    "sno" : 3,
                    "name" : "XYZ",
                    "email" : "xyz@demo.com"
            },
            {
                    "sno" : 4,
                    "name" : "ABC",
                    "email" : "abc@demo.com"
            },
            {
                    "sno" : 5,
                    "name" : "Rohan",
                    "email" : "rohan@example.com"
            }
    ]
}

但我只想要5个子行中的3个，比如

{
    "_id" : ObjectId("4f74737cc3a51043d26f4b90"),
    "id" : "12345",
    "info" : [
            {
                    "sno" : 1,
                    "name" : "ABC",
                    "email" : "abc@example.com"
            },
            {
                    "sno" : 2,
                    "name" : "XYZ",
                    "email" : "xyz@example.com"
            },
            {
                    "sno" : 5,
                    "name" : "Rohan",
                    "email" : "rohan@example.com"
            }
    ]
}

Answer 1

Rohan，MongoDB始终返回您正在搜索的整个文档。您不能只返回找到关键字的数组元素。如果您想这样做，那么您需要确保“info”字段中的所有嵌入文档都在他们自己的集合中。这可能意味着您需要将它们链接回“info”集合中的原始文档。也许是这样的事情：

{
    "sno" : 1,
    "name" : "ABC",
    "email" : "abc@example.com"
    "info_id" : "12345",
},

或者，您当然可以在PHP中进行后处理，以仅获取您想要的行。

Answer 2

也许这是一个好主意？ http://php.net/manual/en/class.mongoregex.php

Answer 3

我尝试了Map Reduce Function，它适用于这类问题代码就是这样：

写一个地图功能

  map=function () 
  {
      filter = [];
      this.info.forEach(function (s) {if (/example/.test(s.email)) {filter.push(s);}});
      emit(this._id, {info:filter});
  }

写一个reduce函数

  reduce=function(key, values) { return values;}

MapReduce功能

  res=db.info.mapReduce(map,reduce,{out:{inline:1}})

输出看起来像：

"results" : [
    {
            "_id" : ObjectId("4f9a2de0ea4a65c3ab85a9d3"),
            "value" : {
                    "info" : [
                            {
                                    "sno" : 1,
                                    "name" : "ABC",
                                    "email" : "abc@example.com"
                            },
                            {
                                    "sno" : 2,
                                    "name" : "XYZ",
                                    "email" : "xyz@example.com"
                            },
                            {
                                    "sno" : 5,
                                    "name" : "Rohan",
                                    "email" : "rohan@example.com"
                            }
                    ]
            }
    }
    ],
    "timeMillis" : 1,
    "counts" : {
            "input" : 3,
            "emit" : 3,
            "reduce" : 0,
            "output" : 3
    },
    "ok" : 1,

现在您可以从

找到您的搜索数据

   printjson(res.results)

Answer 4

你尝试过$（投影）吗？

db.info.find({"info.email":"example"}, {"info.email.$":1})

document

如何使用mongodb搜索内部数组中的字符串？

4 个答案: