title: How do I SUM a UNION ALL Subquery in Oracle
body: <p>For the code below, I'm getting the following error message from Oracle: </p>
  
  <blockquote>
    <p>"ORA-00923: FROM keyword not found where expected".</p>
  </blockquote>
  
  <pre><code>SELECT
      t1.id,
      t1.code,
      SUM(t1.productCount)
  FROM
      (SELECT
          id1,
          code1,
          COUNT(DISTINCT(product)) as productCount1
      FROM
          table1
      GROUP BY
          id1,
          code1
  
      UNION ALL
  
      SELECT
          id2,
          code2,
          COUNT(DISTINCT(product2)) as productCount2
      FROM
          table2
      GROUP BY
          id2,
          code2
  
      UNION ALL
  
      SELECT
          id3,
          code3,
          COUNT(DISTINCT(product3)) as productCount3
      FROM
          table3
      GROUP BY
          id3,
          code3) t1
  GROUP BY
      t1.id,
      t1.code
  </code></pre>
  
  <p>Any advice?</p>