title: Get data by id from firebase
body: <p>I use firebase on node.js .</p>
  
  <p>My given structure should look like this:</p>
  
  <pre><code>{
  ...
  batch-1:
          id-1(suppose):
                       name:...
                       phone:...
          id-2:
               ...
          id-3:
               ...
  batch-2:
          ...
  batch-3:
          ...
  ...
  
  
  batch-n:
         ...
  }
  </code></pre>
  
  <p>How can I get an id-1 object by its identifier in such an architecture?
  Does the database have to go around all the batches?
  Is there a better solution?
  The main task: Create a batch with many objects that will have SHORT and a UNIQUE identifier and optimally receive data by this identifier</p>