title: How to route using [HttpGetAttribute] including the query strings in AspNet.Core WebApi application?
body: <p>I have the following routing, which works on invokation <em><code>/api/demo/info/34</code></em>.</p>
  
  <pre><code>[Route("api/demo")]
  public class Demo : Controller
  {
      [HttpGet("Info/{x}")]
      public JsonResult GetInfos(string x) { ... }
  }
  </code></pre>
  
  <p>Now, I'd like to pass a query string to select the ID, like so: <em><code>/api/demo/info?x=34</code></em>. How should I rephrase the attribute for that?</p>
  
  <p>When I tried entering <em><code>[HttpGet("Info?x={x}")]</code></em>, the error message said that the question mark isn't valid there. I want to resolve it through the attributive approach and routing from the default mapping isn't an option.</p>