## mysql case when then else end 語法 1. 簡單函數? `CASE [col_name] WHEN [value1] THEN [result1]…ELSE [default] END` 2. 搜索函數? `CASE WHEN [expr] THEN [result1]…ELSE [default] END`  ``` SELECT Sname '姓名', CASE Ssex WHEN '男' THEN '歐巴' WHEN '女' THEN '女神' ELSE '人妖' END '性別' FROM student ``` ``` SELECT Sname '姓名', CASE WHEN Ssex = '男' THEN '歐巴' WHEN Ssex = '女' THEN '女神' ELSE '人妖' END '性別' FROM student ``` ``` UPDATE student SET Ssex = ( CASE Ssex WHEN '男' THEN '歐巴' WHEN '女' THEN '女神' ELSE '人妖' END ) ```