arangosh&gt; <span class="hljs-keyword">var</span> key = <span class="hljs-string">'testKey'</span>;
arangosh&gt; db._query(
........&gt; aql<span class="hljs-string">`FOR c IN mycollection FILTER c._key == <span class="hljs-subst">${key}</span> RETURN c._key`</span>
........&gt; ).toArray();
[ 
  <span class="hljs-string">"testKey"</span> 
]