今天敲程式碼的時候，剛好遇到這個問題，寫部落格記一下。

情況如下：性別欄位在資料庫中儲存的是數字，男對應1，女對應0。然後，查詢的時候，我想查詢出男和女兩個字，而不是1和0。

一開始，我寫的sql語句，是直接從查詢出性別對應的數字，sql語句如下：

SELECT 
Employee.Id,
Employee.Account,
Pwd, 
Employee.Name,
Sex,
Email,
Phone,
Position.Name as PositionId,
Team.Name as TeamId,
Store.Name as StoreId,
Enabled
from Employee ,Position,Team, Store 
where Employee.PositionId=Position.Id and Employee.TeamId=Team.Id  and  Employee.StoreId=Store.Id
 

在網友的提示下，我將sql語句修改如下：

SELECT 
Employee.Id,
Employee.Account,
Pwd, 
Employee.Name,
  ( CASE Sex
      WHEN '1' THEN '男'      
      WHEN '0' THEN '女'
      ELSE ' '
   END )as Sex,
Email,
Phone,
Position.Name as PositionId,
Team.Name as TeamId,
Store.Name as StoreId,
 Enabled
from Employee ,Position,Team, Store 
where Employee.PositionId=Position.Id and Employee.TeamId=Team.Id  and  Employee.StoreId=Store.Id
 

在使用了case  when（oracle只用decode函式） 之後，查詢到的性別終於顯示了文字，而不是數字