question: there is a set of data similar to the following
{"sn": "18160481", "status": 1, "updateTime": 1542691932103}
{"sn": "18160482", "status": 2, "updateTime": 1542691932113}
{"sn": "18160483", "status": 2, "updateTime": 1542691932123}
{"sn": "18160484", "status": 3,
how to get the latest updateTime, and count the number of status of 2 through aggregate
I don't know if I understand what I mean to you. The latest updateTime if it refers to the latest for each group grouped according to status , it is written like this:
db.table.aggregate([
{$group: {_id: "$status", updateTime: {$max: "$updateTime"}, count: {$sum: 1}}}
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