title: Symfony / Doctrine findBy
body: <p>Hove to create custom Repository function who query by json field. I have params column in my database who look like this:</p>
  <pre class="lang-json prettyprint-override"><code>&quot;params&quot;: {
      &quot;product&quot;: &quot;stopper&quot;,
      &quot;itemIdentifier&quot;: &quot;&quot;
  }
  </code></pre>
  <p>I want to query record by product value. In this case stopper term.</p>