{"name":"张1","sex":"男"}
{"name":"张2","sex":"男"}
{"name":"张3","sex":"男"}
{"name":"张1","sex":"男"}
{"name":"张2","sex":"男"}
{"name":"张2","sex":"男"}
.......

统计每个姓名的有多少人，怎么写？使用sum 不对吧，用什么那？

   const $ = db.command.aggregate
    db
      .collection('test')
      .aggregate()
      .group({
        _id: '$name',
        totalPrice: $.sum('$name')
      })
      .end()