title: DB2 SQL how to make null value become 0?
body: <p>May I know how to make a null value show in an SQL result as 0?</p>
  
  <pre><code>String SQL = " SELECT A.CNCODE,C.TOTPREM,B.ORDER_AMOUNT,DECIMAL(D.AMOUNT,12,2) AS AMOUNT FROM TB_ORDER A,"+
               " TB_ORDER2 B, TB_ORDER3 C LEFT JOIN TB_ORDER4 D ON C.UKEY2=D.UKEY"+
               " WHERE C.UKEY2='0012254' AND C.UKEY2=B.UKEY2 AND C.UKEY2=A.UKEY "；                
        SQL += " WITH UR";
  </code></pre>
  
  <p>In the current SQL result, amount is shown as "<code>-</code>" indicating NULL; how to make it "0.00"?</p>
  
  <pre><code>===========================================
  CNCODE | TOTPREM | ORDER_AMOUNT | AMOUNT
  ===========================================
  I0012254 |136.54 |       5      |     -
  </code></pre>