陌子曦的专栏

1.数据集合如下所示 { "_id" : ObjectId("61b0ba42ad73bc04fc538bdq”), "userId" : "61af93b3ad73bc04fc538b21”, “schoolName”:”北京大学”, "status" : 1， "createTime" : ISODate("2021-12-08T13:59:20.495Z"), "updateTime" : ISODate("2021-12-08T14:44:16.213Z"), "delete" :

MongoDB语句实现如下： db.myexcel.aggregate([ { "$group": { "_id": { "area": "$area", "name": "$name", "age": "$age" }, "totalFormalNumber": { "$sum": { "$toDouble": "$FormalNumber"

mongodb命令方式： db.myexcel.aggregate([ { "$group": { "_id": null, "totalFormalNumber": { "$sum": { "$toDouble": "$FormalNumber" } }, "count": { "$sum": 1 } } } ]) 结果： { .