先取值，后查詢
select * from
(select num,student_id FROM score where score.course_id IN (SELECT course.cid from course where course.cname='物理')) as Ａ
LEFT join
(select num,student_id FROM score where score.course_id IN (SELECT course.cid from course where course.cname='生物')as W) AS B
on B.student_id=A.student_id;
# 命名錯誤------ Unknown column 'A.student_id' in 'field list'
uj5u.com熱心網友回復：
select * from(select num,student_id FROM score a where a.course_id IN (SELECT cid from course b where b.cname='物理')) as Ａ
LEFT join
(select num,student_id FROM score a where a.course_id IN (SELECT cid from course b where b.cname='生物')) AS B
on B.student_id=A.student_id;
你試試這個
uj5u.com熱心網友回復：
SELECT * FROM(SELECT num,student_id FROM score WHERE score.course_id IN (SELECT course.cid FROM course WHERE course.cname='物理')) Ａ
LEFT JOIN
(SELECT num,student_id FROM score WHERE score.course_id IN (SELECT course.cid FROM course WHERE course.cname='生物')) B
ON B.student_id=A.student_id;
uj5u.com熱心網友回復：
腳本中發現以下兩個錯誤：1. as A處， A字母使用的是全解輸入
2. AS B處， 在AS B處前面的小括號里面，已經有一個AS W了
陳述句嵌套的有點多，建議使用以下形式：
select A.*
FROM score AS A
LEFT JOIN course AS AC ON A.course_id = AC.cid
LEFT JOIN score AS B ON A.student_id = B.student_id
LEFT JOIN course AS BC ON B.course_id = BC.cid
WHERE AC.cname = N'物理' AND BC.cname = N'生物'
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標籤：MySQL
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