如何使用mongodb搜索内部数组中的字符串？

Question

如何多维数组搜索值， 比如我想搜索在MongoDB中 以下数据example关键字我用来从命令

>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" 
      } 
    ] 
} 

获取所有数据现在，找到数据具有example我用命令

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

{ 
    "_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" 
      } 
    ] 
} 

但我想只有3个5个个子行像

{ 
    "_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

我试过的Map Reduce函数，它适用于这类问题的代码是类似的东西：

写地图功能

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

写减少功能

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

MapReduce功能

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

和输出看喜欢：

"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, 

现在你可以从

printjson(res.results) 

Answer 2

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

Answer 3

Rohan，MongoDB始终返回您正在搜索的整个文档。您不能仅仅让它返回发现关键字的数组元素。如果你想这样做，那么你需要确保“info”字段中的所有嵌入文档都在它们自己的集合中。这可能意味着您需要将它们链接回“info”集合中的原始文档。也许类似于：

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

或者，您当然也可以在PHP中进行后处理以仅获取所需的行。

Answer 4

找到搜索的数据你有没有尝试$（投影）？

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

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