Oracle Case 条件函数

select dx.docid,
       case dx.tel_mobile
         when '1%' then
          dx.tel_mobile
         else
          dx.tel
       end 
        as tel,
       dx.xxbh,
       doc.docinfo
  from SWDX_XX_SENDLIST dx, SWDX_FLOW_DOC doc
 where dx.docid = doc.docid
   and dx.sendflag = 0
   and (dx.tel like '1%' or dx.tel_mobile like '1%')

   case dx.tel_mobile
         when '1%' then
          dx.tel_mobile
         else
          dx.tel
   end

这段话的意思就是如果tel_mobile是以1开头的手机，那么我们就得到tel_mobile，否则我们就得到 dx.tel