Question

我是MongoDB的新手并且现在正在学习。在这里，我遇到了以下无法查询的问题。下面是我的JSON数据，当我试图通过使用以下db.ERP.find（{“title”：“ERP”}）找到“标题”：“ERP”时，即使有数据，它也不会获取任何数据。此外，查找数据“标识符”的声明是什么：“0750652071”，“类别”：[“商业与经济学”]。

任何人都可以帮我解决这个问题吗？

Json数据：

{ 
    "_id" : ObjectId("56a6d9c13cd5c314da703c80"), 
    "kind" : "books#volumes", 
    "totalItems" : NumberInt(1088), 
    "items" : [
        {
            "kind" : "books#volume", 
            "id" : "7r2cTflTfpQC", 
            "etag" : "sEiEfpm5JFQ", 
            "volumeInfo" : {
                "title" : "ERP",
                "subtitle" : "The Implementation Cycle", 
                "authors" : [
                    "Stephen Harwood"
                ], 
                "publisher" : "Butterworth-Heinemann", 
                "publishedDate" : "2003", 
                "industryIdentifiers" : [
                    {
                        "type" : "ISBN_10", 
                        "identifier" : "0750652071"
                    }, 
                    {
                        "type" : "ISBN_13", 
                        "identifier" : "9780750652070"
                    }
                ], 
                "readingModes" : {
                    "text" : false, 
                    "image" : true
                }, 
                "pageCount" : NumberInt(183), 
                "printType" : "BOOK", 
                "categories" : [
                    "Computers"
                ], 
                "averageRating" : 4.0, 
                "ratingsCount" : NumberInt(2), 
                }, 
            "saleInfo" : {
                "country" : "US", 
                "saleability" : "NOT_FOR_SALE", 
                "isEbook" : false
            }
         }, 
        {
            "kind" : "books#volume", 
            "id" : "3j86qt9VQ2kC", 
            "etag" : "MQN5u7Pj6yo", 
            "volumeInfo" : {
                "title" : "ERP: Making It Happen", 
                "subtitle" : "The Implementers' Guide to Success with Enterprise Resource Planning", 
                "authors" : [
                    "Thomas F. Wallace", 
                    "Michael H. Kremzar"
                ], 
                "publisher" : "John Wiley & Sons", 
                "publishedDate" : "2002-07-15", 
                "industryIdentifiers" : [
                    {
                        "type" : "ISBN_13", 
                        "identifier" : "9780471217039"
                    }, 
                    {
                        "type" : "ISBN_10", 
                        "identifier" : "0471217034"
                    }
                ], 
                "readingModes" : {
                    "text" : false, 
                    "image" : true
                }, 
                "pageCount" : NumberInt(384), 
                "printType" : "BOOK", 
                "categories" : [
                    "Business & Economics"
                ],
                "averageRating" : 4.0, 
                "ratingsCount" : NumberInt(4), 
                }, 
            "saleInfo" : {
                "country" : "US", 
                "saleability" : "FOR_SALE", 
                "isEbook" : true 
          }
       }
    ]
}

感谢您的帮助！

Answer 1

要搜索tile为ERP的数据，请使用以下语法：

db.collection.find({"items.volumeInfo.title":"ERP"})

使用identifier：0750652071和categories查找数据：[ "Business & Economics"]使用以下语法：

db.collection.find({ "items.volumeInfo.industryIdentifiers.identifier" : "0750652071", "items.volumeInfo.categories" : { $in : [ "Business & Economics"] } })

如果您只想要符合条件的第一项，请在查询{"items.$" : 1}中包含以下字段，如下所示：

db.collection.find(
                    { 
                        "items.volumeInfo.industryIdentifiers.identifier" : "0750652071", 
                        "items.volumeInfo.categories" : { $in : [ "Business & Economics"] } 
                    },
                    { "items.$" : 1 }
                );

Mongodb查找Json数据内循环的命令

1 个答案: