title: Selecting multiple fields in subquery
body: <p>This ABAP code works:</p>
  
  <pre><code>  select *
     into table &lt;sub_result&gt;
    from ADRC
    WHERE ADDRNUMBER
    in ( select ADRNRA from AUFK where (cond_string) ).
  </code></pre>
  
  <p>But this does not:</p>
  
  <pre><code>  select *
     into table &lt;sub_result&gt;
    from ADRC
    WHERE (ADDRNUMBER, MANDT)
    in ( select ADRNRA, MANDT from AUFK where (cond_string) ).
  </code></pre>
  
  <p>AFAIK the tuple syntax <code>(ADDRNUMBER, MANDT)</code> is valid for SQL. Is this not valid in Open SQL of ABAP?</p>
  
  <p>If the tuple syntax is not allowed, what could I do?</p>
  
  <p><strong>P.S.</strong> In Open SQL checking for MANDT is not needed, so this is only sample query. </p>