Firebase数据库未在TableView中加载

Question

对于我正在处理的iOS项目，我使用Firebase作为数据库。我有多个页面，每个页面都有自己的参考，它们工作正常。但是，当我创建最新页面时，该应用程序运行时不会加载任何内容。 tableview是空白的，但是没有错误消息。我引用数据库的方式有问题吗？

代码如下：

import UIKit

import Firebase

class wrestlingController: UIViewController, UITableViewDelegate, UITableViewDataSource {

    var ref = DatabaseReference()

    var wDate = [String]()
    var wTime = [String]()
    var wMatch = [String]()

    var databaseHandle:DatabaseHandle = 0
    var databaseHandle2:DatabaseHandle = 0
    var databaseHandle3:DatabaseHandle = 0


    @IBOutlet var wrestlingTable: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()

        ref = Database.database().reference()

        databaseHandle = ref.child("Wrestle").child("wDates").observe(.childAdded) { (snapshot) in
            let post = snapshot.value as? String
            if let actualPost = post {
                self.wDate.append(actualPost)
            }
        }

        databaseHandle2 = ref.child("Wrestle").child("wTimes").observe(.childAdded) { (snapshot) in
            let post2 = snapshot.value as? String
            if let actualPost2 = post2{
                self.wTime.append(actualPost2)
            }
        }

        databaseHandle3 = ref.child("Wrestle").child("wMatches").observe(.childAdded) { (snapshot) in
            let post3 = snapshot.value as? String
            if let actualPost3 = post3 {
                self.wMatch.append(actualPost3)
                self.wrestlingTable.reloadData()
            }
        }

    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return wMatch.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let wrestlingCell = tableView.dequeueReusableCell(withIdentifier: "wrestlingCell") as! wrestlingCell
        wrestlingCell.wDate.text = wDate[indexPath.row]
        wrestlingCell.wTime.text = wTime[indexPath.row]
        wrestlingCell.wMatch.text = wMatch[indexPath.row]

        return(wrestlingCell)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }




}