How to Write a Left Outer Join with WHERE clause in Pig Latin?
<p>I have two relations with defined schemas.  I wish to find get only the records from relationA that do not exist in relation (see left middle visualization on <a href="https://stackoverflow.com/questions/406294/left-join-and-left-outer-join-in-sql-server?rq=1">this post</a>).</p>

<p>I've tried the two variations below with no success as they both return the error below.  How do I perform this type of operation in Pig?</p>

<blockquote>
  <p>"ERROR 1200 mismatched input 'WHERE' expecting SEMI-COLON."</p>
</blockquote>

<pre><code>join_result = JOIN relationA by (project_id, sequence_id) LEFT OUTER, relationB by (project_id, sequence_id) WHERE relationB (project_id, sequence_id)is null;

join_result = JOIN relationA by (project_id, sequence_id) LEFT OUTER, relationB by (project_id, sequence_id) WHERE (relationB.project_id is null) AND (relationB.sequence_id is null);
</code></pre>