MongoDB 的分组操作 In C#

C#对mongodb的分组查询操作，主要通过脚本或Aggregate方法来实现，以下通过一些实例作解析：

参考资料：http://www.tuicool.com/articles/2iqUZj

　　　　 http://www.cnblogs.com/vnii/archive/2012/08/23/2652891.html
　　　　 http://www.cnblogs.com/zhwl/archive/2013/12/19/3482140.html
1. 根据任务id进行分组，统计每个任务的浏览数量。

　　

public static List<vm_quantityModel> GetMyIncomeDetail(int member_id, int pageIndex, int pageSize, out int totalCount)
{
//筛选条件
IMongoQuery query = Query.And(Query.EQ("member_id", member_id), Query.EQ("mark", 1));

MongoCollection<BsonDocument> myCollection = MongoDBHelper.GetCollection("mstg_record_history");

//分组
Dictionary<string, int> dic_initial = new Dictionary<string, int>();
dic_initial["num"] = 0;
var r = myCollection.Group(
query,
"task_id", //分组的字段
BsonDocument.Create(dic_initial),
BsonJavaScript.Create("function(doc,prev){prev.num++;}"),
null
).ToList();

List<vm_quantityModel> result = new List<vm_quantityModel>();
if (r != null && r.Count > 0)
{
foreach (var item in r)
{
vm_quantityModel m = new vm_quantityModel();
m.task_id = Common.StringHelper.StrToInt(item["task_id"].ToString());
m.valid_count = Common.StringHelper.StrToLong(item["num"].ToString());
result.Add(m);
}
}

totalCount = result.Count;
result = result.OrderByDescending(x => x.task_id).Skip((pageIndex - 1) * pageSize).Take(pageSize).ToList();

return result;
}

2.根据会员编号分组，累加价格的统计

/// <summary>
/// 帮帮赚会员总收益
/// </summary>
/// <param name="memberIds"></param>
/// <returns></returns>
public static List<vm_rankingModel> GetBangZhuanList(List<int> memberIds)
{
var ids = memberIds.ConvertAll<BsonValue>(x => x);
//筛选字段
IMongoQuery query = Query.And(Query.In("member_id", ids), Query.EQ("mark", 1));

MongoCollection<BsonDocument> myCollection = MongoDBHelper.GetCollection("mstg_record_history");

//GroupBy的字段
GroupByBuilder groupbyBuilder = new GroupByBuilder(new string[] { "member_id" });

Dictionary<string, double> dic_M = new Dictionary<string, double>();
dic_M["msum"] = 0.0;
var result_M = myCollection.Group(query, groupbyBuilder, BsonDocument.Create(dic_M),
BsonJavaScript.Create("function(obj,prev){prev.msum += obj.price;}"),
BsonJavaScript.Create("function(obj){obj.sum=obj.msum;delete obj.sum;}")).ToList();

List<vm_rankingModel> result = new List<vm_rankingModel>();
if (result_M != null && result_M.Count > 0)
{
foreach (var item in result_M)
{
double amount = Math.Round(Convert.ToDouble(item["msum"]), 2);
result.Add(new vm_rankingModel
{
member_id = Common.StringHelper.StrToInt(item["member_id"].ToString()),
amount = amount
});
}
}

result = result.OrderByDescending(x => x.amount).ToList();

return result;
}

用Aggregate实现：

public static List<vm_rankingModel> GetRankingList(int top)
{
MongoCollection<BsonDocument> myCollection = MongoDBHelper.GetCollection("mstg_record_history");

//分组获取金额总数
var group = new BsonDocument
{

{ "$group",
new BsonDocument
{
{ "_id", new BsonDocument
{
{
"MemberId","$member_id"
}
}
},
{
"Count", new BsonDocument
{
{
"$sum", "$price"
}
}
}
}
}
};
//筛选条件
var match = new BsonDocument
{
{
"$match",
new BsonDocument
{
{"mark", 1}
}
}
};

var pipeline = new[] { match, group };
var list = myCollection.Aggregate(pipeline);

var matchingExamples = list.ResultDocuments
.Select(x => x.ToDynamic())
.ToList();
List<vm_rankingModel> result = new List<vm_rankingModel>();

//foreach (var example in matchingExamples)
//{
//    var message = string.Format("{0} - {1}", example._id.MyUser, example.Count);
//    Console.WriteLine(message);
//}

if (matchingExamples.Count > 0)
{
foreach (var example in matchingExamples)
{
int member_id = Convert.ToInt32(example._id.MemberId.Value);
double amount = Math.Round(example.Count.Value, 2);
result.Add(new vm_rankingModel
{
member_id = member_id,
amount = amount
});
}
}

result = result.OrderByDescending(x => x.amount).Take(top).ToList();

return result;
}

3. 按日期分组，累加价格的统计

public static List<vm_bangzhuan_detailModel> GetBangZhuanDetails(List<int> memberIds)
{
var ids = memberIds.ConvertAll<BsonValue>(x => x);
//有效浏览数
IMongoQuery query = Query.And(Query.In("member_id", ids), Query.EQ("mark", 1));

MongoCollection<BsonDocument> myCollection = MongoDBHelper.GetCollection("mstg_record_history");

Dictionary<string, double> dic_M = new Dictionary<string, double>();
dic_M["msum"] = 0.0;
var result_M = myCollection.Group(query, BsonJavaScript.Create("function(doc){  var date = new Date(doc.add_time); var dateKey = date.getFullYear()+'年'+(date.getMonth()+1)+'月'+date.getDate();  return {'day':dateKey}; }"), BsonDocument.Create(dic_M),
BsonJavaScript.Create("function(obj,prev){prev.msum += obj.price;}"),
BsonJavaScript.Create("function(obj){obj.sum=obj.msum;delete obj.sum;}")).ToList();

List<vm_bangzhuan_detailModel> result = new List<vm_bangzhuan_detailModel>();
if (result_M != null && result_M.Count > 0)
{
foreach (var item in result_M)
{
double amount = Math.Round(Convert.ToDouble(item["msum"]), 2);
result.Add(new vm_bangzhuan_detailModel
{
day = Convert.ToDateTime(item["day"]),
amount = amount
});
}
}

result = result.OrderByDescending(x => x.day).ToList();

return result;
}