mongodb - Golan and mongo query in mgo -

so have mongo db query works fine:

db.levels.aggregate([{          $match: {                   "_id": {$lt: objectid("56410480f91e505237902dae")}          }, },              { $group:              {                               "_id": {"title": "level 11"},                  "totalamount": { $sum: "$rewardcoins"}             }         }  ]) 

it should rows before give id , based on rewardcoins calculate sum.

now mgo in golang i'm strugling working... i'm going pipe resultset empty.

pipe := c.pipe([]bson.m{{"$match": bson.m{"_id": bson.m{"$lt": level.id}},         "$group": bson.m{"_id":"$title", "totalreward": bson.m{"$sum": "$rewardcoins"}}}})      res :=[]bson.m{}      pipe.all(&res) 

what i'm doing wrong here ? thanks.

update

here how simple rows in db:

{ "_id" : objectid("5613f5ad153678d113d01f4a"), "title" : "level 1", "rewardcoins" : numberlong(1000) } { "_id" : objectid("56159796153678d113d02d60"), "title" : "level 2", "rewardcoins" : numberlong(50000) } 

the structure in go isn't same in other language. if hit enter after every brace or comma, add commas go wants them, , run go fmt, 1 bson.m:

pipe := c.pipe(     []bson.m{         {             "$match": bson.m{                 "_id": bson.m{                     "$lt": level.id,                 },             },             "$group": bson.m{                 "_id": "$title",                 "totalreward": bson.m{                     "$sum": "$rewardcoins",                 },             },         },     }, ) 

another way see there's no }, { before $group in go, whereas there in json-y version.

indenting way seems idea in general; eyes can lost in sea of brackets otherwise.