array of strings sorting as array of Interfaces with mgo in golang

here is my code :

type CatMixing struct {
	Id      bson.ObjectId `json:"id" bson:"_id,omitempty"`
	CatMix []string  `json:"comb"`
}

func main(){
	session, err := mgo.Dial("127.0.0.1")
	if err != nil {
		panic(err)
	}
	defer session.Close()
	session.SetMode(mgo.Monotonic, true)
	c := session.DB("MixiIng").C("Combination")
	var results []bson.M
	err5 := c.Find(nil).Limit(10).All(&results)
	if err5 == nil {

	}
        fmt.Println(results)
	for _,catm := range results {
		fmt.Println(catm)
		for _,catm2 := range catm {
			fmt.Println(reflect.TypeOf(catm2))

		}

	}


}

the problem is that it seems that comb is an array of interfaces :

map[_id:ObjectIdHex("590e5cb36aace327da180c89") comb:[60fps]]
bson.ObjectId
[]interface {}

but in mongo it shows as an array of string :

So my mapping is not working ...
If i try with :

var results []CatMixing

i have the _id but not comb , comb appears as empty

I don't understand why it's not an array of string and why my mapping is not working.

I've added data to mongodb with python :

from pymongo import MongoClient
client = MongoClient()
db = client['MixiIng']
collection = db['Combination']
combination = {}
result = [["60fps"]]
for r in result :
    combination = {"comb":r}
    collection.insert_one(combination)

So i don't understand why comb is not an array of string and how to get it...

thanks and regards

First you can change the results variable from the query using your []CatMixing. Because .All(result interface{}) needs an interace{} argument doesn't mean you can't pass your struct.

Note that interface{} in Go can hold any type including your struct.

try this code :

var results [] CatMixing
err := c.Find(bson.M{}).Limit(10).All(&results)
if err != nil {
   fmt.Fatal(err)
}
fmt.Println(results)