获取匹配的子集和mongodb中的子集数

Question

我有以下文件结构

    {
    "_id" : ObjectId("578a14112acb483c1a0dce0a"),
    "professionalInterests" : [ 
        {
            "_id" : ObjectId("578a063a0068ec0c1320a1de"),
            "interestName" : "Finance and Accounting"
        }, 
        {
            "_id" : ObjectId("578a063a0068ec0c1320a1e7"), 
            "interestName" : "Journalism and Mass Media"
        }, 
        {
            "_id" : ObjectId("578a063a0068ec0c1320a1e5"),
            "interestName" : "Manufacturing Industry"
        }
    ],
    "personalInterests" : [ 
        {
            "_id" : ObjectId("578a063a0068ec0c1320a1d2"),
            "interestName" : "Music"
        }, 
        {
            "_id" : ObjectId("578a063a0068ec0c1320a1d4"),
            "interestName" : "Sports"
        }
    ]
}

我有一些兴趣爱好

var professionalInterests = [ 
            {
                "interestName" : "Finance and Accounting"
            }
];
var personalInterests  = [ 
            {
                "interestName" : "Music"
            }
];

我想检索所有文件，但按匹配的“专业兴趣”和“专业兴趣”与匹配的计数进行排序。 我尝试了$setIntersection但它对我不起作用。 我还尝试了$unwind ， $project ， $size但这不是有效的解决方案。 生成的文档应包含但排序取决于匹配的兴趣（例如，如果匹配“ userA” 2个兴趣并且匹配“ userB” 3个兴趣，则“ userB”在列表中位于上方，然后“ userA”。

{
   professionalInterests : [],//user professional interests
   personalInterests : [],//user personal interest
   matchedProfessionalInterests : [],// contain the matched professional interest
   matchedPersonalInterests : [],// contain the matched personal interest
   matchedProfessionalInterestsCount : number,
   matchedPersonalInterests : number
}

Answer 1

要解决您的问题，您需要使用您提到的运算符来构建聚​​合管道。 这是一个查询，该查询返回您需要的数据：

db.interests.aggregate([{$project: {professionalInterests: 1,
                                personalInterests: 1,
                                matchedProfessionalInterests: {$setIntersection: [["Finance and Accounting", "Data Modeling"], "$professionalInterests.interestName"]},
                                matchedPersonalInterests: {$setIntersection: [["Music"], "$personalInterests.interestName"]}}},
                    {$project: {professionalInterests: 1,
                                personalInterests: 1,
                                matchedProfessionalInterests: 1,
                                matchedPersonalInterests: 1,
                                matchedProfessionalInterestsCount: {$size: "$matchedProfessionalInterests"},
                                matchedPersonalInterestsCount: {$size: "$matchedPersonalInterests"}}},
                    {$sort: {matchedProfessionalInterestsCount: -1, matchedPersonalInterests: -1}}]);

由于我仍然不清楚是哪种兴趣，无论是专业兴趣还是个人兴趣，您想订购结果，因为我已将它们都置于$ sort阶段。 您可以轻松地根据您的要求调整$ sort。 请参阅$ sort运算符文档。