使用MongoDB从Golang中的子对象数组获取值

Question

I am using the mgo.v2 driver with the latest version of MongoDB installed. My document structure is defined like this:

type gameTemplate struct {
ID       bson.ObjectId `bson:"_id" json:"id"`
GameCode string        `bson:"gamecode" json:"gamecode"`
Players  []player      `bson:"players" json:"players"`
}

type player struct {
PlayerID bson.ObjectId `bson:"playerid" json:"playerid"`
Username string        `bson:"username" json:"username"`
Level    int           `bson:"level" json:"level"`
}

How would I go about getting a list of usernames in a particular game (Defined by gamecode)?

Is there a way to get the size of the array and iterate through the elements, or is there a preferred method?

Answer 1

you could get all player with specific game code like this:

players := []gameTemplate{}
err = session.DB(DBname).C(Colloctionname).Find(bson.M{}).All(&players) 

as you defined each players has username and size of players slice is the number of username which has specific game code.

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ps:
be careful and change DBname and Colloctionname whit your Database and collection name and use session of your databse connection be