一道Adv问题
Item 6
The table WORK.PILOTS contains the following data:
WORK.PILOTS
Id Name Jobcode Salary
--- ------ ------- ------
001 Albert PT1 50000
002 Brenda PT1 70000
003 Carl PT1 60000
004 Donna PT2 80000
005 Edward PT2 90000
006 Flora PT3 100000
The data set was summarized to include average salary based on jobcode:
Jobcode Salary Avg
------- ------ -----
PT1 50000 60000
PT1 70000 60000
PT1 60000 60000
PT2 80000 85000
PT2 90000 85000
PT3 100000 100000
Which SQL statement could NOT generate this result?
答案如下
C.
select
Jobcode,
Salary,
(select avg(Salary)
from WORK.PILOTS
group by Jobcode) as Avg
from WORK.PILOTS
order by Id

请问各位，该程序问题在哪里？谢谢！