title: Graphql: Find value in array field of object
body: <p>I want to filter list value ['500', '600'] in tags field.
  Tags field is []varchar.</p>
  
  <p>Like in mongodb: <code>{tags: {$in: ['500', '600']}}</code></p>
  
  <p>I try in graphql. but its not working</p>
  
  <pre><code>  questions(where: {tags: {_in: ["500ae"]}}) {
      id
    }
  }
  </code></pre>
  
  <p>Result error:</p>
  
  <pre><code>{
   "errors": [
     {
       "extensions": {
         "path": "$",
         "code": "constraint-error"
       },
       "message": "type \"_varchar[]\" does not exist"
     }
   ]
  }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/FD171.png" rel="nofollow noreferrer">enter image description here</a></p>