如何获得按“值"降序排序的 map/reduce 结果?值?如果也使用列表函数可以实现吗?

2022-01-13 00:00:00 mapreduce couchdb javascript couchdb-futon

我有这样的视图地图和减少:地图:

I have view map and reduce like this: Map:

   function(doc) {
           if(doc.type){
            var usersLength = doc.users.length;
            for (var i = 0; i < usersLength ; i++) {
                    emit([doc.users[i].userid,doc.Service.ownId], 1);
                }
            }
        }

减少:

 function(keys, values, rereduce)
    {
      return sum(values);
    }

然后像这样调用视图:_design/aaa/_view/getUserId?group=true&group_level=2&startkey=["111111"]&endkey=["111111",{}]

我可以得到下面的结果集:

I can get the result set below:

{"rows":[
{"key":["111111",""],"value":7},
{"key":["111111","FFFF26"],"value":1},
{"key":["111111","FFFF44"],"value":7},
{"key":["111111","FFFF34"],"value":2}
]}

但是，我想让上面的结果集按值"值的降序排序.如果还使用列表功能可以实现吗?预期结果如下:

However, I want to get the result set above sorted within descending order of the "value" value. if also using list function can achieve that? the following would be expected results:

{"rows":[
{"key":["111111",""],"value":7},
{"key":["111111","FFFF44"],"value":7},
{"key":["111111","FFFF34"],"value":2},
{"key":["111111","FFFF26"],"value":1}
]}

推荐答案

如果要对结果集进行排序，则必须按值降序排序，可以使用比较器回调进行排序:

If you want to sort the result set you have to one that is sorted by value descending you can sort with a comparator callback:

// ES6 Syntax
let originalResult = {
"rows":[
  {"key":["111111",""],"value":7},
  {"key":["111111","FFFF26"],"value":1},
  {"key":["111111","FFFF44"],"value":7},
  {"key":["111111","FFFF34"],"value":2}
]}

let newResult = {
  rows: originalResult.rows.sort((a, b) => b.value - a.value)
}

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