和PL/SQL相同的"DECODE"DB2要如何用

和PL/SQL相同的"DECODE"DB2要怎么用
select   SUM(DECODE(TWMS_INVTRANSLINE.itemtype,
                                          'Material ',
                                              TWMS_INVTRANSLINE.statactitemqty   ))   Price
    from   TWMS_INVTRANSLINE  
  GROUP   BY   TWMS_INVTRANSLINE.ITEMDESC


这句SQL用DB2的语法要怎么写

------解决方案--------------------------------------------------------
select ITEM,
sum(case itemtype when 'Material ' then statactitemqty else 0 end) Price
from TWMS_INVTRANSLINE
GROUP BY TWMS_INVTRANSLINE.ITEM