title: How to join tables in Hive using find_in_set
body: <p>Table A contains a column <code>id(string)</code>
  Table B contains a column <code>ids(string)</code>,like <code>"id1,id2,id3"</code></p>
  
  <p>to join A and B, I want A.id can be found in B.ids:</p>
  
  <pre><code>select count(1) from 
  (select id from A) as t1
  join
  (select ids from B) as t2
  on find_in_set(t1.id, t2.ids) != 0;
  </code></pre>
  
  <p>then I see :</p>
  
  <blockquote>
    <p>[Error 10017]: Line 1:91 Both left and right aliases encountered in JOIN '0' </p>
  </blockquote>
  
  <p>if I change <code>!=</code> to <code>=</code>, the error is still the same.</p>
  
  <p>How to solve this problem?</p>