如何获取mongoDB集合的排名位置？

我有一个 mongoDB 集合，如下所示：

{
    "_id": 1,
    "name": "John Doe",
    "company": "Acme",
    "email": "[email protected] /cdn-cgi/l/email-protection",
    "matches": [171844, 169729, 173168, 174310, 168752, 174972, 172959, 169546]
}
{
    "_id": 2,
    "name": "Bruce Wayne",
    "company": "Wayne Enterprises",
    "email": "[email protected] /cdn-cgi/l/email-protection",
    "matches": [171844, 232333, 233312, 123456]
}
{
    "_id": 3,
    "name": "Tony Stark",
    "company": "Stark Industries",
    "email": "[email protected] /cdn-cgi/l/email-protection",
    "matches": [173844, 155729, 133168, 199310, 132752, 139972]
}
{
    "_id": 4,
    "name": "Clark Kent",
    "company": "Daily Planet",
    "email": "[email protected] /cdn-cgi/l/email-protection",
    "matches": [169729, 174310, 168752]
}
{
    "_id": 5,
    "name": "Lois Lane",
    "company": "Daily Planet",
    "email": "lois.lan[email protected] /cdn-cgi/l/email-protection",
    "matches": [172959, 169546]
}

我需要获取经过筛选的用户列表，但有一个键可以根据用户拥有的“匹配”记录数显示用户的“排名”位置。 应该有一个global ranking位置和一个company ranking位置。

期望的结果应该是这样的（例如过滤 company='Daily Planet'）：

{
    _id: 4,
    name: 'Clark Kent',
    company: 'Daily Planet',
    email: '[email protected] /cdn-cgi/l/email-protection',
    points: 3,     // <=
    globalRank: 4, // <=
    companyRank: 1 // <=
},
{
    _id: 5,
    name: 'Lois Lane',
    company: 'Daily Planet',
    email: '[email protected] /cdn-cgi/l/email-protection',
    points: 2,     // <=
    globalRank: 4, // <=
    companyRank: 2 // <=
}

请注意，Clark Kent 在全球排名中排名第 4，因为他有 3 场比赛（John Doe、Bruce Wayne 和 Tony Stark 的比赛比他多），并且在公司排名中排名第一，因为他比任何 Daily Planet 用户的比赛都多。 。

然而，经过几天的研究，我还是找不到办法。 （我什至不知道如何仅进行全球排名或公司排名）。

关于如何解决这个问题，或者如何以不同的方式解决这个问题有什么想法吗？

基本思想是首先对点进行排序points正如你所做的那样，跟进$push将它们放入一个数组中。这确保了元素按排序顺序插入。然后我们$unwind https://docs.mongodb.com/manual/reference/operator/aggregation/unwind/使用includeArrayIndex属性来生成排序数组中与排名相对应的元素的索引。

使用上述逻辑的管道如下（尝试逐步进行以更好地理解）：-

aggregate([
    {
        $project: {
            _id: 1,
            name: "$name",
            company: "$company",
            email: "$email",
            points: {
                $size: "$matches"
            }
        }
    }, {
        $sort: {
            points: -1
        }
    },

    {
        $group: {
            _id: {},
            arr: {
                $push: {
                    name: '$name',
                    company: '$company',
                    email: '$email',
                    points: '$points'
                }
            }
        }
    }, {
        $unwind: {
            path: '$arr',
            includeArrayIndex: 'globalRank',
        }
    }, {
        $sort: {
            'arr.company': 1,
            'arr.points': -1
        }
    }, {
        $group: {
            _id: '$arr.company',
            arr: {
                $push: {
                    name: '$arr.name',
                    company: '$arr.company',
                    email: '$arr.email',
                    points: '$arr.points',
                    globalRank: '$globalRank'
                }
            }
        }
    }, {
        $unwind: {
            path: '$arr',
            includeArrayIndex: 'companyRank',
        }
    }, {
        $project: {
            _id: 0,
            name: '$arr.name',
            company: '$arr.company',
            email: '$arr.email',
            points: '$arr.points',
            globalRank: '$arr.globalRank',
            companyRank: '$companyRank'
        }
    }

]);

查询的输出是

/* 1 */
{
    "companyRank" : NumberLong(0),
    "name" : "Bruce Wayne",
    "company" : "Wayne Enterprises",
    "email" : "[email protected] /cdn-cgi/l/email-protection",
    "points" : 4,
    "globalRank" : NumberLong(2)
}

/* 2 */
{
    "companyRank" : NumberLong(0),
    "name" : "Tony Stark",
    "company" : "Stark Industries",
    "email" : "[email protected] /cdn-cgi/l/email-protection",
    "points" : 6,
    "globalRank" : NumberLong(1)
}

/* 3 */
{
    "companyRank" : NumberLong(0),
    "name" : "Clark Kent",
    "company" : "Daily Planet",
    "email" : "[email protected] /cdn-cgi/l/email-protection",
    "points" : 3,
    "globalRank" : NumberLong(3)
}

/* 4 */
{
    "companyRank" : NumberLong(1),
    "name" : "Lois Lane",
    "company" : "Daily Planet",
    "email" : "[email protected] /cdn-cgi/l/email-protection",
    "points" : 2,
    "globalRank" : NumberLong(4)
}

/* 5 */
{
    "companyRank" : NumberLong(0),
    "name" : "John Doe",
    "company" : "Acme",
    "email" : "[email protected] /cdn-cgi/l/email-protection",
    "points" : 8,
    "globalRank" : NumberLong(0)
}

这里的排名是从 0 开始的。