mongodb组每2周

Question

这是每周对数据进行分组的方法:

 transactions.aggregate({   
    [
        {$match: {status: "committed"}},
        {$group: {
            _id: {
                $year: "$date",                                 
                $week: "$date"                          
            },
            count: {$sum: 1},
            start_date: {$min: "$date"},
            end_date: {$max: "$date"}                               
        }}
    ]
});     

问题是，如何每 2 周分组一次并获得计数？

谢谢。

根据接受的答案的正确方法

感谢 Mzzl，这适用于每 2 周进行一次分组。以下是完整版。

db.transactions.aggregate([
    {$match: {status: "committed"}},
    {$project: {
        twoweekperiod: {
            $subtract: [
              {$week: "$date"}, {$mod: [{$week: "$date"}, 2] }
            ]
        },
        date:1,
        status:1
   }},
   {$group: {
        _id: {
            year: {$year: "$date"},                                 
            twoweek: "$twoweekperiod"                      
        },
        count: {$sum: 1},
        start_date: {$min: "$date"},
        end_date: {$max: "$date"}                               
    }}
])

Answer 1

假设 $week 包含周数，您可以创建一个“每两周”的数字，并按此分组。试试这样的:

{ 
    $project: {
        twoweekperiod: {
            $subtract: [
              '$week', {$mod: ['$week', 2] }
            ]
        }, status:1, date:1, etc...
   }
}

我不知道如何在 mongo 查询中进行整数除法，因此我改为从 weeknumber 中减去 weeknumber mod 2，以获得每隔一周更改一次的数字，而不是每周。然后，您可以尝试按此数字进行分组。