У меня есть этот запрос на моей таблице, и он возвращает таблицу, приведенную ниже
SELECT sub.Subject_Name, count(sa.Attendance) AS Lectures_Attended FROM student_attendance sa
INNER JOIN TeacherSubjects ts on (sa.TeacherSubject_ID = ts.TeacherSubject_ID)
INNER JOIN Subjects sub on(ts.Subject_ID = sub.Subject_ID)
where sa.Student_ID = 1 AND sub.Semester = '8th-Semester' AND sa.Attendance=1
GROUP by sa.TeacherSubject_ID
UNION ALL
SELECT sub.Subject_Name, count(sa.Attendance) AS Total_Lectures FROM student_attendance sa
INNER JOIN TeacherSubjects ts on (sa.TeacherSubject_ID = ts.TeacherSubject_ID)
INNER JOIN Subjects sub on(ts.Subject_ID = sub.Subject_ID)
where sa.Student_ID = 1 AND sub.Semester = '8th-Semester'
GROUP by sa.TeacherSubject_ID
SubjectName LecturesAttended
Php 2
Php 3
Теперь мне не нужен второй ряд, т.е. Php | 3
Мне нужно, чтобы таблица была показана так
SubjectName LecturesAttended TotalLectures
Php 2 3
Вам просто нужно уменьшить ваш запрос до:
SELECT
sub.Subject_Name,
COUNT(IF(sa.Attendance=1,1,NULL)) AS Lectures_Attended,
COUNT(*) Total_Lectures
FROM student_attendance sa INNER JOIN TeacherSubjects ts ON (sa.TeacherSubject_ID = ts.TeacherSubject_ID)
INNER JOIN Subjects sub ON (ts.Subject_ID = sub.Subject_ID)
WHERE sa.Student_ID = 1 AND sub.Semester = '8th-Semester'
GROUP by sa.TeacherSubject_ID;
Увидеть Функция MySQL IF () о том, как функция if работает в MySQL.
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