title: Firebase update data not working
body: <p>Hi I wanted to update the firebase data, but when I update it insert to a new data instead of updating the specific data that I set which is the lastname equal to 'hoo'</p>
  
  <pre><code>fb.orderByChild("Lastname").equalTo('hoo').once("value", function(snapshot){
    console.log(snapshot.ref());
    console.log(snapshot.val());
    // var snapref = snapshot.ref();
    snapshot.ref().update({
      FirstName: 'yoyo1'  
    });
  })
  </code></pre>
  
  <p>Edit:</p>
  
  <pre><code>fb.orderByChild("Lastname").equalTo('hoo').once("child_added", function(snapshot){
      console.log(snapshot.ref());
      console.log(snapshot.val());
      // var snapref = snapshot.ref();
      snapshot.ref().update({
        FirstName: 'yoyo1'      
      });  
    })
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/gbpEO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gbpEO.png" alt="enter image description here"></a></p>
  
  <p>See the bottom code the new edit code that works by using <strong>'child_added'</strong> not using <strong>value</strong></p>