Mongodb聚合 时间分组(转载)

// Requires official MongoShell 3.6+
use MediaNetDB;
db.getCollection("TestCollection").aggregate(
    [
        { 
            "$project" : {
                "Day" : {
                    "$dateToString" : {
                        "format" : "%Y-%m-%d", 
                        "date" : "$AddDateTime"
                    }
                }, 
                "Time" : {
                    "$dateToString" : {
                        "format" : "%H:%M:%S:%L", 
                        "date" : "$AddDateTime"
                    }
                }
            }
        }, 
        { 
            "$group" : {
                "_id" : {
                    "Day" : "$Day"
                }, 
                "count" : {
                    "$sum" : 1.0
                }
            }
        }, 
        { 
            "$project" : {
                "_id" : 0.0, 
                "Day" : "$_id.Day", 
                "Count" : "$count"
            }
        }, 
        { 
            "$sort" : {
                "Count" : -1.0
            }
        }
    ], 
    { 
        "allowDiskUse" : false
    }
);
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版权声明：本文为CSDN博主「Waldenz」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/enter89/article/details/84937951