title: UNION query in DB2
body: <p>My query is: </p>
  
  <pre><code>SELECT BRAND,BRAND_GROUP, SUB_BRAND ,SUM(INCOME) AS TOTAL_INCOME FROM
  "tema".MMT WHERE BRAND_GROUP IS NULL AND SUB_BRAND IS NULL GROUP BY
  BRAND,BRAND_GROUP,SUB_BRAND
  
  UNION
  SELECT BRAND,BRAND_GROUP, SUB_BRAND ,SUM(INCOME) AS TOTAL_INCOME FROM
  "tema".BGT WHERE BRAND_GROUP IS NULL AND SUB_BRAND IS NULL GROUP BY 
  BRAND,BRAND_GROUP,SUB_BRAND;
  </code></pre>
  
  <p>and my output is :</p>
  
  <pre><code>BRAND BRAND_GROUP SUB_BRAND TOTAL_INCOME 
  ----- ----------- --------- ------------ 
  GBS   NULL        NULL             10000
  SWG   NULL        NULL             10000
  GBS   NULL        NULL             20000
  STG   NULL        NULL             20000
  GTS   NULL        NULL             30000
  </code></pre>
  
  <p>The problem is that i have 2 categories of BRAND and I want to have just 1. Like this :</p>
  
  <pre><code>Brand       Brand_Group     Sub_brand       Total_Income
  GBS                  -          -           30000
  STG                  -          -           20000
  GTS                  -          -           30000
  SWG                  -          -           10000
  </code></pre>
  
  <p>Can someone help me with an ideea?</p>