示例一

SELECT 學號, 姓名,
 等級=
    CASE
    WHEN 總學分 IS NULL THEN ‘尚未選課’
       WHEN 總學分 < 50 THEN ‘不及格’
        WHEN 總學分 >=50 and 總學分<=52 THEN ‘合格’
        ELSE ‘優秀’
    END  FROM  XS    WHERE 專業名=’計算機’

示例二

update employee
set e_wage =
 case
  when job_level = ’1’ then e_wage*1.08
  when job_level = ’2’ then e_wage*1.07
  when job_level = ’3’ then e_wage*1.06
  else e_wage*1.05
 end

示例三

select a, (case a when 1 then '中' else '國' end) AS B  from table1