Mysql SELECT子句和solve中的子查询;子查询返回多行;

Mysql SELECT子句和solve中的子查询;子查询返回多行;,mysql,select,subquery,Mysql,Select,Subquery,期望输出: 2014-11-12 2 2014-11-18 2 2014-11-23 1 我的代码: SELECT Attendance.Attend_Date, (SELECT COUNT(Attendance.AttendDet_Type) as P FROM Student, Attendance WHERE Student.Stud_ID = Attendance.Stud_ID AND Student.Stud_Class = '1A1' AND Attendance.A

期望输出:

2014-11-12 2 
2014-11-18 2 
2014-11-23 1
我的代码:

SELECT Attendance.Attend_Date, (SELECT COUNT(Attendance.AttendDet_Type) as P 
FROM Student, Attendance 
WHERE Student.Stud_ID = Attendance.Stud_ID 
AND Student.Stud_Class = '1A1' 
AND Attendance.Attend_Date BETWEEN '2014-01-01' AND '2014-12-01' 
AND Attendance.AttendDet_Type = 'P' 
GROUP BY Attendance.Attend_Date
) as T
FROM Student, Attendance
WHERE Student.Stud_ID = Attendance.Stud_ID
AND Student.Stud_Class = '1A1'
AND Attendance.Attend_Date BETWEEN '2014-01-01' AND '2014-12-01'
GROUP BY Attendance.Attend_Date

有人能帮我吗?谢谢。

我的答案。谢谢大家

SELECT Attendance.Attend_Date, 
COUNT(CASE WHEN Attendance.AttendDet_Type = 'P' THEN Attendance.Attend_Date ELSE null END)AS P, 
COUNT(CASE WHEN Attendance.AttendDet_Type = 'A' THEN Attendance.Attend_Date ELSE null END)AS A, 
COUNT(CASE WHEN Attendance.AttendDet_Type = 'C' THEN Attendance.Attend_Date ELSE null END)AS C, 
COUNT(CASE WHEN Attendance.AttendDet_Type = 'MC' THEN Attendance.Attend_Date ELSE null END)AS MC 
FROM Student, Attendance 
WHERE Student.Stud_ID = Attendance.Stud_ID 
AND Student.Stud_Class = '" & DropDownList13.SelectedValue & "' 
AND Attendance.Attend_Date BETWEEN '" & Label5.Text & "' 
AND '" & Label6.Text & "' 
GROUP BY Attendance.Attend_Date

您可能不想让分组人在您的子选择中?(这就是为什么格式化很重要)我喜欢人们在没有输入的情况下提供所需的输出。