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我有以下 SQL 表达式：

SELECT PROFESSOR_NAME, SUBJECT_NAME, NUMBER_OF_CREDITS, PERCENT,
  (SELECT COUNT(STUDENTID)
    FROM SUBJSTUD
    WHERE SUBJSTUD.SUBJECTID = SUBJECT.SUBJECT_ID) AS NUMBER_OF_STUDENTS,
  0.4*NUMBER_OF_CREDITS*PERCENT*(
    SELECT COUNT(STUDENTID)
    FROM SUBJSTUD
    WHERE SUBJSTUD.SUBJECTID = SUBJECT.SUBJECT_ID)*18/120) AS PAYMENT_PER_SUBJECT,
  SUM(0.4*NUMBER_OF_CREDITS*PERCENT*(
    SELECT COUNT(STUDENTID) 
    FROM SUBJSTUD
    WHERE SUBJSTUD.SUBJECTID = SUBJECT.SUBJECT_ID)*18/120) AS PAYMENT_PER_PROFESSOR
FROM SUBJECT, PROFESSOR, TEACHES
WHERE PROFESSOR.PROFESSOR_ID = TEACHES.PROFESSORID 
AND SUBJECT.SUBJECT_ID = TEACHES.SUBJECTID
AND POCETOK_UCEBNA = :UCEBNA_GODINA
AND SEMESTAR = :SEMESTAR
AND PROFESsOR.STUDISKAPROGRAMA = :STUDISKAPROGRAMA
GROUP BY PROFESSOR_NAME, SUBJECT_NAME, NUMBER_OF_CREDITS, PERCENT

参数取自列表框。如果没有 SUM，它可以正常工作，但我需要最后一次计算来生成一份报告，该报告将汇总每位教授每门学科的所有付款。问题可能出在子表达式 ( SELECT COUNT(STUDENTID) FROM SUBJSTUD WHERE SUBJSTUD.SUBJECTID = SUBJECT.SUBJECT_ID) 中，但我不知道如何解决。

4

1 回答 1

0

您的查询中缺少左括号，请尝试：

SELECT PROFESSOR_NAME, SUBJECT_NAME, NUMBER_OF_CREDITS, PERCENT,
  (SELECT COUNT(STUDENTID)
    FROM SUBJSTUD
    WHERE SUBJSTUD.SUBJECTID = SUBJECT.SUBJECT_ID) AS NUMBER_OF_STUDENTS,
  (0.4*NUMBER_OF_CREDITS*PERCENT*(
    SELECT COUNT(STUDENTID)
    FROM SUBJSTUD
    WHERE SUBJSTUD.SUBJECTID = SUBJECT.SUBJECT_ID)*18/120) AS PAYMENT_PER_SUBJECT,
  SUM(0.4*NUMBER_OF_CREDITS*PERCENT*(
    SELECT COUNT(STUDENTID) 
    FROM SUBJSTUD
    WHERE SUBJSTUD.SUBJECTID = SUBJECT.SUBJECT_ID)*18/120) AS PAYMENT_PER_PROFESSOR
FROM SUBJECT, PROFESSOR, TEACHES
WHERE PROFESSOR.PROFESSOR_ID = TEACHES.PROFESSORID 
AND SUBJECT.SUBJECT_ID = TEACHES.SUBJECTID
AND POCETOK_UCEBNA = :UCEBNA_GODINA
AND SEMESTAR = :SEMESTAR
AND PROFESsOR.STUDISKAPROGRAMA = :STUDISKAPROGRAMA
GROUP BY PROFESSOR_NAME, SUBJECT_NAME, NUMBER_OF_CREDITS, PERCENT;
于 2013-10-03T17:16:35.590 回答