IOS Swift 3 (firebase database) pickerView not working when loading data from database

In my code I have two pickerViews where I am fetching data from firebase where the first picker is hard-coded with data values, where based on those values ​​I want sub-tables from firebase to be fetched and I am not able to get them right now ... Please help me please .... Thanks in Advance

Here is my code. Please let me know where I am going wrong.

 @IBOutlet weak var map: MKMapView!
@IBOutlet weak var designText: UITextField!
@IBOutlet weak var nameText: UITextField!
@IBOutlet weak var designPicker: UIPickerView!
@IBOutlet weak var namePicker: UIPickerView!
@IBOutlet weak var designListButton: UIButton!
var normaletmds = [String]()
var normaltdes = [String]()
var location : Any?
var refhandle: UInt?
var refhandle1: UInt?
var key1: Any?
var values: Any?
var getKey = [String]()
var keys: [String]?
var nameString = [String]()
var adminstring = [String]()
var globalValue: String?
var nameValue: Any?
var latitudevalue : Any!
var longitudevalue : Any!
var ref : FIRDatabaseReference?
var ref1 : FIRDatabaseReference?
var latitude1: CLLocationDegrees = CLLocationDegrees()
var longitude2: CLLocationDegrees = CLLocationDegrees()
var locationManager = CLLocationManager()
override func viewDidLoad(){

ref = FIRDatabase.database().reference().child("users").child("Aishwarya")
refhandle = ref?.observe(FIRDataEventType.value, with: { (snapshot) in
let postDict = snapshot.value as? [String : AnyObject] ?? [:]
for (key, value) in postDict
{
    if (key == "llattitude")
    {
        self.latitudevalue = value
        print("latitude",self.latitudevalue!)
    }
    else if (key == "llongitude")
    {
        self.longitudevalue = value
        print("logitude",self.longitudevalue!)
    }
    else if (key == "namee")
    {
        self.nameValue = value
    }

}
@IBAction func designlistButton(_ sender: Any) {
    if designPicker.isHidden == false{
        designPicker.isHidden = true
        ref = FIRDatabase.database().reference().child("users").child("users2").child(designText.text!)
        refhandle = ref?.observe(FIRDataEventType.value, with: { (snapshot) in
            let postDict = snapshot.value as? [String : AnyObject] ?? [:]
        print("postDict=",postDict)
            for (key, value) in postDict
            {
              self.getKey.append(key)
            }
            print("getvalue=", self.getKey)
               self.getValue()
        })
    }
    else
    {
        designPicker.isHidden = false
    }
}
 func getValue()
{
    for get in getKey{
    ref = FIRDatabase.database().reference().child("users").child("users2").child(designText.text!).child(get)
        refhandle = ref?.observe(FIRDataEventType.value, with: { (snapshot) in
            let postDict = snapshot.value as? [String : AnyObject] ?? [:]
            print("postDict=",postDict)
            for (key, value) in postDict
            {
               // self.getKey?.append(key)
                if key == "title"
                {
                    self.nameString.append(value as! String)
                }
            }
            print("namestring=",self.nameString)
        })
    }
     print("gevalue")
}
@IBAction func namePicker(_ sender: Any) {

    if namePicker.isHidden == false
    {
        namePicker.isHidden = true
    }
    else
    {
        namePicker.isHidden = false
    }
}

func numberOfComponents(in pickerView: UIPickerView) -> Int
{
    return 1
}

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int
{
    var countrows : Int = nameString.count
    if pickerView == designPicker {
        countrows = self.adminstring.count
    }
    return countrows
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?
{
    if pickerView == designPicker {
        let titleRow = adminstring[row]
        return titleRow
    } else if pickerView == namePicker {
        let titleRow = nameString[row]
        return titleRow
    }
    return ""
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
    if pickerView == designPicker {
        self.designText.text = self.adminstring[row]
    } else if pickerView == namePicker {
        self.nameText.text = self.nameString[row]
    }
}