title: Issue with subquery - All expressions must have explicit name in teradata
body: <p>Don't understand what is going wrong. Can someone please help with the below query. I am new to Teradata SQL</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th style="text-align: left;">account_id</th>
  <th style="text-align: center;">trans_date_fnl</th>
  <th style="text-align: right;">date (Currentdate)</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: left;">1234</td>
  <td style="text-align: center;">2021-05-06</td>
  <td style="text-align: right;">2021-06-03</td>
  </tr>
  <tr>
  <td style="text-align: left;">12345</td>
  <td style="text-align: center;">2021-05-29</td>
  <td style="text-align: right;">2021-06-03</td>
  </tr>
  <tr>
  <td style="text-align: left;">12346</td>
  <td style="text-align: center;">2021-05-28</td>
  <td style="text-align: right;">2021-06-03</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>SQL</p>
  <pre><code>SELECT TRANSDATE FROM
  (
    SELECT TRANS_DATE_fnl, CURRENT_DATE, (CURRENT_DATE - TRANS_DATE_fnl) AS &quot;TRANSDATE&quot;
    FROM financial_db.fin_trans_puneet
    WHERE extract(year from TRANS_DATE_fnl) = '2021' AND extract(MONTH from TRANS_DATE_fnl) = '5'
    GROUP BY TRANS_DATE_fnl
  ) a
  </code></pre>
  <p>Error :-</p>
  <blockquote>
  <p>Executed as Single statement. Failed [3707 : 42000] Syntax error,
  expected something like a name or a Unicode delimited identifier or an
  'UDFCALLNAME' keyword between ')' and ';'.   Elapsed time =
  00:00:00.007</p>
  </blockquote>
  <p>Output :-</p>
  <p>I need to have the customer who have done transaction between 5 to 10 days along with the transaction date</p>