Question

我需要加入3个收藏集。Teams，Schedule_Results，Stadiums。我有数据文件团队（TeamID，团队，大陆，联赛，人口） SCHEDULE_RESULTS（GameID，MatchType，MatchDate，SID，TeamID1，TeamID2，Team1_Score，Team2_Score）体育场（SID，SName，SCity，SCapacity）

x = db.TEAMS.aggregate([
    {"$lookup":
        {
            "from": "SCHEDULE_RESULTS",
            "localField": "TeamID",
            "foreignField": "TeamID1",
            "as": "part1",
        }
    },
    {"$lookup":
        {
            "from": "SCHEDULE_RESULTS",
            "localField": "TeamID",
            "foreignField": "TeamID2",
            "as": "part2",
        }
    },
    {
        "$out":"PART1_COLLECTION"
    }
])
z = db.PART1_COLLECTION.aggregate([
    {"$lookup":
        {
           "from": "STADIUMS",
           "localField": "SID",
           "foreignField": "SID",
           "as": "part3"
        }
    },
    {
        "$project":{
            "_id":0,
            "Team" : 1,
            "TeamID" : 1,
            "SID" :1,
            "SName" : "$part3.SName",
            "SCity" : "$part3.SCity"
        }
    },
    {
        "$out":"PART2_COLLECTION"
    }
])

I need output as 
    {
        "TeamName": "Russia",
        "matchScores": [
            {
                "matchDate": "2018-06-14",
                "stadiumName": "Luzhniki Stadium",
                "cityName": "Moscow",
                "teamName": "Russia",
                "teamScore": 5,
                "oppTeamName": "Saudi Arabia",
                "oppTeamScore": 0
            },
            {
                "matchDate": "2018-06-19",
                "stadiumName": "Saint Petersburg Stadium",
                "cityName": "Saint Petersburg",
                "teamName": "Russia",
                "teamScore": 3,
                "oppTeamName": "Egypt",
                "oppTeamScore": 1
            },
            {
                "matchDate": "2018-06-25",
                "stadiumName": "Samara Arena",
                "cityName": "Samara",
                "teamName": "Russia",
                "teamScore": 0,
                "oppTeamName": "Uruguay",
                "oppTeamScore": 3
            },
            {
                "matchDate": "2018-07-01",
                "stadiumName": "Luzhniki Stadium",
                "cityName": "Moscow",
                "teamName": "Russia",
                "teamScore": 1,
                "oppTeamName": "Spain",
                "oppTeamScore": 1
            },
            {
                "matchDate": "2018-07-07",
                "stadiumName": "Fisht Stadium",
                "cityName": "Sochi",
                "teamName": "Russia",
                "teamScore": 2,
                "oppTeamName": "Croatia",
                "oppTeamScore": 2
            }
        ]
    } 
for each Team.
Iam getting the output as

{  
    '_id':ObjectId('5d4468329fec4efe3e156817'),
    'TeamID':'A1',
    'Team':'Russia',
    'Continent':'Europe',
    'League':'UEFA',
    'part1':[  
        {  
            '_id':ObjectId('5d4469179fec4efe3e156e02'),
            'GameID':'G1',
            'Groups':'A',
            'MatchDate':'2018-06-14',
            'SID':'S1',
            'TeamID1':'A1',
            'TeamID2':'A2',
            'Team1_Score':5,
            'Team2_Score':0
        },
        {  
            '_id':ObjectId('5d4469179fec4efe3e156e09'),
            'GameID':'G17',
            'Groups':'A',
            'MatchDate':'2018-06-19',
            'SID':'S2',
            'TeamID1':'A1',
            'TeamID2':'A3',
            'Team1_Score':3,
            'Team2_Score':1
        },
        {  
            '_id':ObjectId('5d4469179fec4efe3e156e35'),
            'GameID':'G59',
            'Groups':'Q',
            'MatchDate':'2018-07-07',
            'SID':'S3',
            'TeamID1':'A1',
            'TeamID2':'D3',
            'Team1_Score':2,
            'Team2_Score':2
        }
    ],
    'part2':[  
        {  
            '_id':ObjectId('5d4469179fec4efe3e156e1b'),
            'GameID':'G33',
            'Groups':'A',
            'MatchDate':'2018-06-25',
            'SID':'S8',
            'TeamID1':'A4',
            'TeamID2':'A1',
            'Team1_Score':3,
            'Team2_Score':0
        },
        {  
            '_id':ObjectId('5d4469179fec4efe3e156e2d'),
            'GameID':'G51',
            'Groups':'X',
            'MatchDate':'2018-07-01',
            'SID':'S1',
            'TeamID1':'B2',
            'TeamID2':'A1',
            'Team1_Score':1,
            'Team2_Score':1
        }
    ],
    'part3':[  

    ]
}

我是MongoDB的新手。任何人都可以请帮我在这

Answer 1

请尝试：

    db.getCollection('TEAM').aggregate([
    {
        $lookup: {
            from: "SCHEDULE_RESULTS",
            let: { teamID: "$TeamID" },
            pipeline: [
                {
                    $match:
                    {
                        $expr:
                        {
                            $or:
                                [
                                    { $eq: ["$TeamID1", "$$teamID"] },
                                    { $eq: ["$TeamID2", "$$teamID"] }
                                ]
                        }
                    }
                }
            ],
            as: "team_StadiumData"
        }
    }, { $unwind: { path: '$team_StadiumData' } },
    {
        $lookup: {
            from: "STADIUM",
            let: { stadiumID: "$team_StadiumData.SID" },
            pipeline: [
                {
                    $match:
                    {
                        $expr:
                        {
                            $eq: ["$SID", "$$stadiumID"]
                        }
                    }
                }
            ],
            as: "finalData"
        }
    },
    { $addFields: { 'team_StadiumData.teamName':'$Team', 'team_StadiumData.stadiumName': { $arrayElemAt: ["$finalData.SName", 0] }, 'team_StadiumData.stadiumCity': { $arrayElemAt: ["$finalData.SCity", 0] }} },
    { $group: { _id: '$TeamID', team_StadiumData: { $push: '$team_StadiumData' }, docs: { $first: '$$ROOT' } } },
    { $addFields: { 'docs.team_StadiumData': '$team_StadiumData' } },
    { $replaceRoot: { newRoot: '$docs' } },
    { $project: { team_StadiumData: 1,Team: 1, _id: 0 } }
])

如果您需要来自 TEAM 的文档，而该文档在 SCHEDULE_RESULTS 中没有匹配的记录，那么您需要添加一个选项：preserveNullAndEmptyArrays: true $unwind第一个阶段的$lookup。

合并文档中的两个数组

1 个答案: