Mysql數據透視表與where條款

select student_id, class_id, section_id, exam_date, exam_id, 
     sum(number*(1-abs(sign(subject-1)))) as sub1, 
     sum(number*(1-abs(sign(subject-2)))) as sub2, 
     sum(number*(1-abs(sign(subject-3)))) as sub3, 
     sum(number*(1-abs(sign(subject-4)))) as sub4, 
     sum(number*(1-abs(sign(subject-5)))) as sub5, 
     sum(number*(1-abs(sign(subject-6)))) as sub6 
from result 
where class_id = '7' and section id = '3' and YEAR(exam_date) = '2012' and exam_id = '3' 
GROUP BY student_id

我有一個問題，當我用where子句過濾所有數值得到0，如果我運行查詢沒有where子句結果將很好，但從所有數據庫。如何使用where子句過濾查詢？任何人都可以幫助我嗎？Mysql數據透視表與where條款

來源

2012-08-07 Zia

你需要按過類標識碼

SELECT * FROM ( 
select student_id, class_id, 
     sum(number*(1-abs(sign(subject-1)))) as sub1, 
     sum(number*(1-abs(sign(subject-2)))) as sub2, 
     sum(number*(1-abs(sign(subject-3)))) as sub3, 
     sum(number*(1-abs(sign(subject-4)))) as sub4, 
     sum(number*(1-abs(sign(subject-5)))) as sub5, 
     sum(number*(1-abs(sign(subject-6)))) as sub6 
from result GROUP BY student_id,class_id) m 
where class_id = '7'

來源

2012-08-07 09:32:33 Madhivanan

在哪裏包裝查詢。

SELECT * FROM (
select student_id, class_id, 
     sum(number*(1-abs(sign(subject-1)))) as sub1, 
     sum(number*(1-abs(sign(subject-2)))) as sub2, 
     sum(number*(1-abs(sign(subject-3)))) as sub3, 
     sum(number*(1-abs(sign(subject-4)))) as sub4, 
     sum(number*(1-abs(sign(subject-5)))) as sub5, 
     sum(number*(1-abs(sign(subject-6)))) as sub6 
from result GROUP BY student_id) m 
where class_id = '7'

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2012-08-07 09:31:02 sel

Mysql數據透視表與where條款

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