您的位置：首页 > 数据库

数据库里类switch语句和三元运算符的使用(case)

2012-11-07 23:58 531 查看

-- oracle

SELECT

SUBSTR(msterialLogId,1,2) || '-' || SUBSTR(msterialLogId,3,2) || '-' || SUBSTR(msterialLogId,5,2) || '-' || SUBSTR(msterialLogId,7,3) AS "编号" ,

DECODE(mClass,'A',TO_CHAR(mDosage,'99999'),' ') AS "甲材料的数量" ,

DECODE(mClass,'B',TO_CHAR(mDosage,'99999'),' ') AS "乙材料的数量" ,

DECODE(mClass,'C',TO_CHAR(mDosage,'99999'),' ') AS "丙材料的数量" ,

DECODE(mClass,'D',TO_CHAR(mDosage,'99999'),' ') AS "丁材料的数量" ,

DECODE(mClass,'E',TO_CHAR(mDosage,'99999'),' ') AS "戊材料的数量"

FROM mdosage;

-- mysql

SELECT

CONCAT(SUBSTR(msterialLogId,1,2) , '-', SUBSTR(msterialLogId,3,2) , '-' , SUBSTR(msterialLogId,5,2) , '-' , SUBSTR(msterialLogId,7,3)) AS "编号",

CASE WHEN mClass = '甲' THEN mDosage ELSE " " END AS "甲材料的数量" ,

CASE WHEN mClass = '乙' THEN mDosage ELSE " " END AS "乙材料的数量" ,

CASE WHEN mClass = '丙' THEN mDosage ELSE " " END AS "丙材料的数量" ,

CASE WHEN mClass = '丁' THEN mDosage ELSE " " END AS "丁材料的数量" ,

CASE WHEN mClass = '戊' THEN mDosage ELSE " " END AS "戊材料的数量"

FROM mdosage;

结果如下：

内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理

标签：

相关文章推荐

新的分享

章节导航