mysql查詢如何求出出勤狀態值

Question

我是mysql新手。在上表中，我必須SUM attendance_status(column)取決於像

01/05/2013 att_stat=0 
01/05/2013 att_stat=1 
02/05/2013 att_stat=0 
02/05/2013 att_stat=1 

它的工作相當不錯的日期時THR只有3當我插入第四一個它不工作

SELECT SUM(Attendance_Status) as total FROM student_attendance1 Where Attendance_Status='1' and Date= '"+datevalue+"'";' 

Answer 1

基本上你接近只是記錄必須把GROUP BY

SELECT 
    SUM(Attendance_Status) AS total 
FROM student_attendance1 
WHERE Attendance_Status = '1' 
    AND DATE = '"+datevalue+"'" 
GROUP BY DATE