Mysql 用于计算每位研究人员提交的总数量的查询
我有3个关于提交和研究人员的表格 提交表格:Mysql 用于计算每位研究人员提交的总数量的查询,mysql,sql,count,Mysql,Sql,Count,我有3个关于提交和研究人员的表格 提交表格: SubmissionID, Type, Title, Status, Comment, CapturedOnRIMS, NumberOfAuthors, NumberOfWitsAuthors, TotalPages, PagesInPreamble, PagesInText, NumberOfChapters, Location, PublicationID, CESMID, SubmissionDate 研究人员表: ResearcherID,
SubmissionID, Type, Title, Status, Comment, CapturedOnRIMS, NumberOfAuthors, NumberOfWitsAuthors, TotalPages, PagesInPreamble, PagesInText, NumberOfChapters, Location, PublicationID, CESMID, SubmissionDate
研究人员表:
ResearcherID, FirstName, Surname, RegistrationDate, QualificationType, JobName, Availability, SchoolID
ResearcherSubmission(关系表):
我试图创建一个查询,显示每个研究人员提交的总数量。一个研究者可以有许多提交,一个提交可以由许多研究者完成,因此关系表
期望输出:
Name Number of Submission
John Doe 14
William Smith 10
Ellie Carter 12
Susan Wright 10
只需
加入
表格并按分组即可:
select r.FirstName, r.LastName, count(*) as no_of_sub
from Researcher r
join ResearcherSubmission rs on r.ResearcherID = rs.ResearcherID
join Submission s on s.SubmissionID = rs.SubmissionID
group by r.FirstName, r.LastName
你必须表现出你自己的努力。我非常确信,如果您遵循基本的SQL教程,您可以自己找到这个问题的答案。
select r.FirstName, r.LastName, count(*) as no_of_sub
from Researcher r
join ResearcherSubmission rs on r.ResearcherID = rs.ResearcherID
join Submission s on s.SubmissionID = rs.SubmissionID
group by r.FirstName, r.LastName