CODEWITHSUNDEEP
c#mongodbmongodb-.net-driver
Behrad Farsi
Behrad Farsi

Reputation: 1110

Calculating sum in MongoDB and C# driver

I want to calculate sum of a field in mongodb via C# driver, While meeting a certain condition and i don't have a clue how to work this out. What i need would be something like this:

var collection = Db.GetCollection<T>(key);
var sumValue = collection.Find(new QueryDocument("Checked", true))
                         .Aggregate(new BsonDocument ("$Sum", "Debit"));

But I don't know how to make this work. Any help is appreciated.

Upvotes: 1

Views: 6390

Answers (1)

rubenfa
rubenfa

Reputation: 851

If you don't want to calculate locally after retrieve the results, you have to use Aggregation Framework. Please, check the sintax, because I haven't tested it.

var match = new BsonDocument 
                { 
                    { 
                        "$match", 
                        new BsonDocument 
                            { 
                                {"Checked", "true"}                             
                            } 
                    } 
                };


var group = new BsonDocument 
                { 
                    { 
                        "$group", 
                        new BsonDocument 
                            { 
                                {"_id", new BsonDocument {"_id","$_id"}},
                                {"sum", new BsonDocument {"$sum","$Debit"}
                            } 
                    } 
                };

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

Here you have more examples.

Upvotes: 1

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