Question

到目前为止我的查询是

SELECT callSign,event,rubric,score 
  FROM scores LEFT JOIN candidates 
    ON scores.candidateID=candidates.id 
  WHERE candidateID IN 
    (SELECT id 
      FROM candidates 
    WHERE assessmentID='1321') 
  ORDER BY candidateID,event

返回如下数据集：

callSign    event                 score
V021    Amazing Race Planning       5
V021    Amazing Race Planning       3
V021    Amazing Race Planning       5
V021    Individual Analyst Exam     3
V021    PSA                         5
V021    Team Analyst Exam           5
V021    Team Analyst Exam           5
V021    Team Analyst Exam           3
V021    Team Analyst Exam           5
V022    PSA                         1
V022    Team Tech Exam              5
V022    Team Tech Exam              3

我正在寻找的是每个候选人加上每个事件的分数，所以它看起来像：

callSign        event              score
V021    Amazing Race Planning       13
V021    Individual Analyst Exam     3
V021    PSA                         5
V021    Team Analyst Exam           18
V022    PSA                         1
V022    Team Tech Exam              8

我确定我需要某种SUM()和GROUP BY的组合，但我似乎无法弄明白。然后我需要ORDER BY所有类别中得分最高的候选人

注意：有多个候选人

Answer 1

其他答案也是正确的，但我会删除IN .. subselect语句。这是不必要的。

按照您要分组的字段进行分组，并将您想要的字段相加。

SELECT callSign, event, SUM(score) score

FROM scores 

     JOIN candidates 
     ON scores.candidateID = candidates.id 

WHERE candidates.assessmentID = '1321'

GROUP BY callSign, event

ORDER BY candidateID, event

Answer 2

SELECT callSign,event, SUM(score) 
  FROM scores LEFT JOIN candidates 
    ON scores.candidateID=candidates.id 
  WHERE candidateID IN 
    (SELECT id 
      FROM candidates 
    WHERE assessmentID='1321') 
  GROUP BY event, callSign
  ORDER BY candidateID,event

通常，主要分组（在您的情况下为event）是第一列。但是，由于您所需的结果集具有相同callSign的多行，因此它必须是次要分组列，而不是主要分组列。

如果您希望主要分组适合候选人，请在查询中包含候选字段，并将其包含在此类分组GROUP BY candidateID, event, callSign

中

Answer 3

SELECT callSign,event,rubric,SUM(score) 
  FROM scores LEFT JOIN candidates 
    ON scores.candidateID=candidates.id 
  WHERE candidateID IN 
    (SELECT id 
      FROM candidates 
    WHERE assessmentID='1321') 
GROUP BY callSign,event,rubric
ORDER BY candidateID,event

您基本上只需要将您未汇总的所有其他列添加到该组中。

EDIT。抱歉把小组放在了错误的地方。

Answer 4

只是一个猜测......

 SELECT callSign
      , event
      , SUM(score) total
   FROM scores s
   LEFT 
   JOIN candidates c
     ON c.id = s.candidateID
    AND c.assessmentID=1321
  GROUP
     BY callsign
      , event;

每个事件的每个候选人的SUM得分列

4 个答案: