javascript MongoDB在一小时之间获得

Posted 2021-05-03

db.getCollection('submission').aggregate([{
    $project: {
        hour: {
            $hour: "$processing_at"
        }
    }
}, {
    $match: {
        hour: {
            "$in": [18]
        }
    }
}, {
    $group: {
        _id: null,
        total: {
            $sum: 1
        }
    }
}])