title: OrientDb check if edge exists
body: <p>In OrientDB Studio I am trying to write a function to check if an edge exists between two vertices. If the query finds a hit, it should return true, if there is no hit it should return false. Each vertex has a unique url within an embeddedSet. This is the field used to ID the vertex. </p>
  
  <p>How to query for the edge? How to return true or false edge exist?</p>
  
  <p>This code works, if I know the RID.</p>
  
  <pre><code>select from E where (in = #14:29 and out = #15:15) OR (in = #15:15 and out = #14:29);
  </code></pre>
  
  <p>This code works as long as the urlSet field is NOT a url.</p>
  
  <pre><code>select from E where out IN (select from v where urlSet contains 'A') and in IN (select from v where urlSet contains 'B');
  </code></pre>
  
  <p>When I try to search for the url's using this code</p>
  
  <pre><code>select from E where out IN (select from v where urlSet contains 'https:\/\/url1.com/a/something') and in IN (select from v where urlSet contains 'https:\/\/url2.com/b/something');
  </code></pre>
  
  <p>I receive this error:</p>
  
  <blockquote>
    <p>com.orientechnologies.orient.core.sql.OCommandSQLParsingException: Error on parsing command at position #35: Invalid keyword 'FROM' Command: select from E where out IN (select from v where urlSet contains 'https://url1.com/a/something') and in IN (select from v where urlSet contains 'https://url2.com/b/something'); -------------------------------------------^ </p>
  </blockquote>