sql - Group By Rollup 抑制额外的数据行

Question

我在 Oracle 11g 数据库上。

询问：

SELECT s.id, s.grade_level, 
((1990+substr(sg.termid,1,2))||'-'||(1991+substr(sg.termid,1,2))) as  "School Year",
SUM(sg.earnedcrhrs) as "Credits"

FROM students s
JOIN storedgrades sg ON s.id = sg.studentid

WHERE s.schoolid = 109
AND s.id = '3466'
AND s.enroll_status = 0
AND sg.schoolid = 109

GROUP BY ROLLUP(s.id, s.grade_level, substr(sg.termid,1,2))
ORDER BY s.id, substr(sg.termid,1,2)

输出：

有没有办法可以编写我的查询，以便不产生第 5 行或第 6 行？每个学生我只需要一个小计（ID 列）。

Answer 1

我得到了 Sanjay Misbra 和 Alan Beaulieu的 O'Reilly 的Mastering Oracle SQL的副本。根据他们的文档，我实际上以稍微不同的方式做到了这一点......

我将 GROUP BY 行从

GROUP BY ROLLUP(s.id, s.grade_level, substr(sg.termid,1,2))

至

GROUP BY s.id, s.grade_level, ROLLUP(substr(sg.termid,1,2))

Answer 2

这有点棘手。尝试这个：

SELECT s.id, s.grade_level, 
((1990+substr(sg.termid,1,2))||'-'||(1991+substr(sg.termid,1,2))) as  "School Year",
SUM(sg.earnedcrhrs) as "Credits"

FROM students s
JOIN storedgrades sg ON s.id = sg.studentid

WHERE s.schoolid = 109
AND s.id = '3466'
AND s.enroll_status = 0
AND sg.schoolid = 109

GROUP BY ROLLUP(s.id, (s.grade_level, substr(sg.termid,1,2)))
ORDER BY s.id, substr(sg.termid,1,2);

（不同的是我把s.grade_level, substr(sg.termid,1,2)子句GROUP BY放在括号里）

总的来说，我强烈推荐 Tim Hall 的这篇文章：Rollup, Cube and GROUPING functions