I'm new to setting up firebase's realtime database, and I'm trying to access the content from a message to display in the app.
Here is how my database is structured:
I want to access "content" for each of the messages with the fewest value for "numberofresponses."
let ref: DatabaseReference! = Database.database().reference(withPath: "messagepool")
ref.queryOrdered(byChild: "numberofresponses").observeSingleEvent(of: .value, with: { snapshot in
if !snapshot.exists() {
print("no snapshot exists")
return }
print(snapshot)
The above code correctly prints the "messagepool," but I want the specific content value from each of the branches. I seem to be missing something. What is the correct way to do this? Thanks
CodePudding user response:
When you execute a query against the Firebase Database, there will potentially be multiple results. So the snapshot contains a list of those results. Even if there is only a single result, the snapshot will contain a list of one result.
So in your closure/completion handler you will need to loop over snapshot.children
to get at the individual result snapshot(s):
ref.queryOrdered(byChild: "numberofresponses").observeSingleEvent(of: .value, with: { snapshot in
if !snapshot.exists() {
print("no snapshot exists")
return
}
for childSnapshot in querySnapShot.children.allObjects as! [DataSnapshot] {
print(childSnapshot.key)
print(childSnapshot.value)
guard let value = childSnapshot.value as? [String: Any] else { return }
do {
guard let content = value["content"] as? String,
...
}
}
}
Also see: