1、行转列
max/sum加上group by【注：在工作当中很少用到存储过程，更多的是用java等语言配合mysql解决实际问题，所以就不说存储过程的方式】
代码：
-- 行转列：主要是通过max/sum实现的，如果要动态可以借助java，写个for循环。循环传值【列：以时间位列，显示近15天的出库量】
-- 方法一
SELECT s_name,max(case when c_name='java' then score else 0 end) java,max(case when c_name='c#' then score else 0 end) cc,
max(case when c_name='php' then score else 0 end) php
FROM user_score_info GROUP BY s_name;
SELECT s_name,sum(case when c_name='java' then score else 0 end) java,sum(case when c_name='c#' then score else 0 end) cc,
sum(case when c_name='php' then score else 0 end) php
FROM user_score_info GROUP BY s_name;
-- 方法二
select distinct a.s_name ,IFNULL((select score from user_score_info b where b.s_name = a.s_name and c_name="java"),0) java,
IFNULL((select score from user_score_info b where b.s_name = a.s_name and c_name="c#"),0) cc,
IFNULL((select score from user_score_info b where b.s_name = a.s_name and c_name="php") ,0) php from user_score_info a;
2、列转行：【主要用到union】
sql脚本
-- 主要使用union实现的
select user_name ,"java" course,java_SCORE score from test_tb_grade2
UNION select user_name ,"c#" course,c_score score from test_tb_grade2
UNION select user_name ,"php" course,php_SCORE score from test_tb_grade2
order by user_name,course
select user_name ,"java" course,java_SCORE score from test_tb_grade2
UNION all select user_name ,"c#" course,c_score score from test_tb_grade2
UNION all select user_name ,"php" course,php_SCORE score from test_tb_grade2
order by user_name,course
