oracle case when 在sql中的使用

select
FullDepartmentName,
   YearBudget    ,
   SupplementaryBudget    ,
   TotalSum    ,
   BudgetDate,
   case jidu
     when 'JANUARYBUDGET' then 1 
     when 'FEBRUARYBUDGET' then 2
     when 'MARCHBUDGET' then 3 
     when 'APRILBUDGET' then 4 
     when 'MAYBUDGET' then 5 
     when 'JUNEBUDGET' then 6 
     when 'JULYBUDGET' then 7 
     when 'AUGUSTBUDGET' then 8 
     when 'SEPTEMBERBUDGET' then 9 
     when 'OTOBERBUDGET' then 10 
     when 'NOVEMBERBUDGET' then 11 
     when 'DECEMBERBUDGET' then 12
     else 00
     end case,
   jidu, 
   xiaoshou
      from  excelmodel
      unpivot (xiaoshou for jidu in (JanuaryBudget,februaryBudget,marchBudget,aprilBudget,mayBudget,juneBudget,julyBudget,augustBudget
      ,septemberBudget,otoberBudget,novemberBudget,decemberBudget) )
    where  YearBudget=9000.00
    and FullDepartmentName='运营部'

格式：

  case 变量
     when '值1' then  doSomeThing
     when '值2' then doSomeThing
     ....
     else doSomeThing
     end 【case】,