title: Retrieve Data from Firebase using where Query in Swift 4
body: <p><a href="https://i.stack.imgur.com/M4JKP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/M4JKP.png" alt="image"></a></p>
  
  <pre><code>let ref = Database.database().reference(withPath: "user")
  ref.observeSingleEvent(of: .value, with: { snapshot in
  
      if !snapshot.exists() { return }
  
      print(snapshot) // Its print all values including Snap (User)
  
      print(snapshot.value!)
  
      let username = snapshot.childSnapshot(forPath: "full_name").value
      print(username!)
  
  })
  </code></pre>