Ambiguous Use of Subscript (Swift 3)

Question

I am using the subscript in the following code incorrectly for this Firebase data pull, but I can\'t figure out what I am doing wrong. I get an error of Ambiguous use of su

Answer 1

Taking Frank's feedback into account, here is the actual working code I used that follows that approach in case it's helpful.

// Log user in
if let user = FIRAuth.auth()?.currentUser {

   let uid = user.uid
   // values for vars sevenDaysAgo and oneDayAgo set here

   ...

   let historyRef = self.ref.child("historyForFeedbackLoop/\(uid)")
        historyRef.queryOrdered(byChild: "Unix Date").queryStarting(atValue: sevenDaysAgo).queryEnding(atValue: oneDayAgo).observeSingleEvent(of: .value, with: { snapshot in

            if (snapshot.value is NSNull) {
                print("user data not found")
            }
            else {

                 for child in snapshot.children {

                    let data = child as! FIRDataSnapshot
                    let value = data.value! as! [String:Any]
                    self.arrayOfUserSearchHistoryIDs.append(value["Unique ID Event Number"] as! Int)
                 }
            }
   })
}