與內部連接的SQL計數

Question

我有一個缺席者的表，並且該表存儲那些缺席者的studentids。

從這個表格中我必須找到總的參加者和總缺席者，爲此我剛加入了包含特定部分的最大容量的部分表格。

因爲我這個查詢是

select COUNT(Attendance.studentid) as Absentees 
     ,Sections.Max-count(studentid) as Presentees 
from Attendance 
inner join Students 
on students.StudentId=Attendance.StudentId 
inner join Sections 
on Sections.CourseId=students.CourseId 
group by Sections.Max 

它的做工精細，同樣的道理我怎麼能找到性別明智presentees /缺席......性別列是學生表，任何人都可以給我一些想法，在此先感謝

Answer 1

只是性別欄添加到您的select ...列和group by，你會一行結束了對每個性別：

select COUNT(Attendance.studentid) as Absentees, 
     Sections.Max-count(studentid) as Presentees, 
     Students.Gender as Gender 
from Attendance 
inner join Students 
on Students.StudentId=Attendance.StudentId 
inner join Sections 
on Sections.CourseId=Students.CourseId 
group by Sections.Max, Students.Gender