关于SQL如果有底据就修改，没有就添加的处理

关于SQL如果有数据就修改，没有就添加的处理
MERGE INTO tvsms.vsms_goods_t a
  USING ( select '44467890' goods_id,'10' goods_suttle,'assadf' goods_pname from dual) c
    ON (c.goods_id=a.goods_id)
  WHEN MATCHED THEN
      update set GOODS_SUTTLE=c.goods_suttle,goods_time=sysdate,GOODS_PNAME=c.goods_pname
where a.goods_id=c.goods_id
  WHEN NOT MATCHED THEN
    insert (goods_id,goods_suttle,goods_pname,goods_uid,goods_time)
values(c.goods_id,c.goods_suttle,c.goods_pname,'',sysdate);