我正在运行地图缩减操作并以坏数据结束。这里是我的地图和减少功能:使用嵌套对象缩小MongoDB地图
var map_analytics = function() {
var key = this.owner;
if (this.apikey == null) {
var value = {api_call_with_key: 0, api_call_without_key: 1};
} else {
var value = {api_call_with_key: 1, api_call_without_key: 0};
}
emit(key, value);
};
var reduce_analytics = function(key_owner, api_calls) {
today = new Date();
firstofmonth = new Date(today.getFullYear(), today.getMonth(), 1);
reduced_val = {period: firstofmonth, analytics: {api_call_with_key: 0, api_call_without_key: 0}};
api_calls.forEach(function(value) {
reduced_val.analytics.api_call_with_key += value.api_call_with_key;
reduced_val.analytics.api_call_without_key += value.api_call_without_key;
});
return reduced_val;
};
现在,当我跑我的地图减少:
db.statistics.mapReduce(map_analytics, reduce_analytics, {out: { reduce: "analytics" }, query: { request_date: { $gte: firstofmonth}}})
我得到这个:
{
"_id" : ObjectId("5136d880136b961c98c9a62f"),
"value" : {
"period" : ISODate("2013-05-01T06:00:00Z"),
"analytics" : {
"api_call_with_key" : NaN,
"api_call_without_key" : NaN
}
}
}
任何想法,为什么我得到的NaN而不是实际值?
这更简单的版本的作品:
var reduce_analytics = function(key_owner, api_calls) {
reduced_val = {api_call_with_key: 0, api_call_without_key: 0};
api_calls.forEach(function(value) {
reduced_val.api_call_with_key += value.api_call_with_key;
reduced_val.api_call_without_key += value.api_call_without_key;
});
return reduced_val;
};
,并产生
{
"_id" : ObjectId("5143b2c8136b9616343dacec"),
"value" : {
"api_call_with_key" : 0,
"api_call_without_key" : 2,
"total_api_calls" : 2
}
}
我怎么能输出更复杂的对象?
并牢记减少函数可以被称为零,一次或一次以上每个键值。 – 2013-05-08 04:42:31
我刚刚在这里发现了这个:http://stackoverflow.com/a/7340000/1563654。这是正确的答案。谢谢。 – 2013-05-08 05:21:53