SQL帮助。如何排列同一行上的值，将一列向上移动？

Question

我有问题让列排队，start_time是end_time之上的一行。

这是我的代码：

SELECT B.NAME 
     ,MAX(case when DESCRIPTION = 'Green' then Final_Value end) as Start_Time 
     ,MAX(case when DESCRIPTION = 'Red' then Final_Value end) as End_Time 
      FROM mydata a 
      JOIN ref_val B 
      ON A.ref_res = B.ref_res  
     WHERE B.COMPANY = 'abc' 
     GROUP BY B.NAME 

这就是我想要得到

The result looks like this: 
    Name  Start_time    End_time   
1 John  5/6/15 6:30 
2 John2  5/7/15 4:30   5/6/15 8:30   
3 Ben   5/8/15 2:30   5/7/15 7:25 
4 Ben2  5/9/15 3:10   5/8/15 4:10 

I want it to look like this: 

    Name  Start_time    End_time    
1 John  5/6/15 6:30   5/6/15 8:30 
2 John2  5/7/15 4:30   5/7/15 7:25   
3 Ben   5/8/15 2:30   5/8/15 4:10 
4 Ben2  5/9/15 3:10   5/9/15 5:20 

Answer 1

使用窗口函数LEAD。在这种情况下，最直接的做法是将当前查询嵌套为已写入，然后在外部查询中应用分区。请参阅：

http://mysqlserverteam.com/mysql-8-0-2-introducing-window-functions/

Answer 2

一个模式会有所帮助，但我怀疑是驱动表不应该是mydata A，而是ref_val b，使集团通过与MAX更有意义。根据实际模式，我可能完全错误：

SELECT B.NAME 
    ,MAX(case when DESCRIPTION = 'Green' then Final_Value end) as Start_Time 
    ,MAX(case when DESCRIPTION = 'Red' then Final_Value end) as End_Time 
     FROM ref_val B 
     JOIN mydata A 
     ON A.ref_res = B.ref_res  
    WHERE B.COMPANY = 'abc' 
    GROUP BY B.NAME