I have a collection of user documents, each with an embedded array of clients. Each object in the array has a clientID.
I wanted to retrieve the user document with a client, in the clients array, that has a clientID matching a passed clientID.
But all the examples I have come across just retrieve the object instead of returning the document. I wanted to do this using the mgo library
var results []model.Clients
err := db.C("users").Find(nil).Select(bson.M{"clients": bson.M{"$elemMatch":q }}).All(&results)
The above returns just a clients array. But I wanted a users array.
[
{
"userID": "1",
clients: [
{
"clientID": "12",
"data": {},
"customers": [
"customerID": "0123",
"data": {
}
]
},
{
"clientID": "123",
"data": {},
"customers": [
"customerID": "0123",
"data": {
}
]
}
]
},
{
"userID": "2",
clients: [
{
"clientID": "12",
"data": {},
"customers": [
"customerID": "0123",
"data": {
}
]
},
{
"clientID": "13",
"data": {},
"customers": [
"customerID": "0123",
"data": {
}
]
}
]
}
]
Query.Select() enables selecting which fields should be retrieved for the results, not for specifying filter criteria. Filter criterial should be passed to Collection.Find().
var results []model.User
err := db.C("users").Find(bson.M{"clients": bson.M{"$elemMatch":q}}).All(&results)
You may also use "clients.clientID" to designate the clientID in the clients array:
var results []model.User
err := db.C("users").Find(bson.M{"clients.clientID": "12"}).All(&results)