如何通过SQL语句查询查询表1，以表2的形式显示？每个人每周的工时求和，将第n周转换成行。

Question

Answer 1

1.先将表1数据用group by 姓名、周分组；
select t.name, t.周, sum(t.工时) as 工时 from table t group by t.name,t.周;

参考自：
MySQL如何优化GROUP BY http://www.data.5helpyou.com/article237.html

2.再将结果进行转列：
select t.name as "姓名",
MAX(CASE 星期 WHEN 1 THEN sum(t.工时) ELSE 0 END ) as "第一周",
MAX(CASE 星期 WHEN 2 THEN sum(t.工时) ELSE 0 END ) as "第二周"
from table t group by t.name,t.周；

参考自：
MySQL行转列、列转行举例 http://www.data.5helpyou.com/article390.html