title: Apollo GraphQL, when fetching typeerror: is undefined
body: <p>I'm new to GraphQL, I can't figure out why when I request to get data, for example <code>data.category.products</code>, I get the correct output, but for example, if I request <code>data.category.products.prices</code>, I will get this error: <em>TypeError: data. category.products.prices is undefined</em></p>
  <p>My Query:</p>
  <pre><code>query AllCategory{
    category {
      products {
        id
        prices {
          currency {
            label
          }
          amount
        }
      }
    }
  }
  </code></pre>
  <p>Doesn't give errors in Playground</p>
  <p>Here is the schema:
  <a href="https://i.stack.imgur.com/jmUD5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jmUD5.png" alt="enter image description here" /></a></p>
  <p>And actually how I call: (this is with an error)</p>
  <pre><code>export default function App() {
  
     const {data} = useQuery(QUERIES)
  
     return (
      
       &lt;div className=&quot;App&quot;&gt;
         {data.category.products.prices.map((shop) =&gt; (
           &lt;p key={shop.currency.label}&gt;{shop.amount}&lt;/p&gt;
         ))}
       &lt;/div&gt;
     );
  }
  </code></pre>
  <p>There is no error here:</p>
  <pre><code>{data.category.products.map((shop) =&gt; (
     &lt;p key={shop.id}&gt;{shop.id}&lt;/p&gt;
  ))}
  </code></pre>
  <p>I`m using apollo client</p>