计算计数，然后计算总计数MySql的总和

Question

My Query

$sql = 'SELECT status FROM tablename';

And the result

------------
status
------------
assigned
assigned
assigned
assigned
assigned
accepted
accepted
completed
completed
completed
completed
completed

Now i can find the total count of each status

SELECT status, COUNT(status) AS cnt
FROM tname
GROUP BY b.statusName
HAVING (cnt >= 1)

This will give

---

status     cnt
--------------
accepted    2
assigned    5
completed   5

How do i sum only completed and accepted count?

Answer 1

This is called conditional summing, when you place the condition within the sum() function:

SELECT SUM(IF(status IN ('accepted','assigned'),cnt,0)) as sum_of_acc_asg
FROM    
    (SELECT status, COUNT(status) AS cnt
    FROM tname
    GROUP BY b.statusName
    HAVING (cnt > 1)) t

Or you can use where to filter the subquery first:

SELECT SUM(cnt) as sum_of_acc_asg
FROM    
    (SELECT status, COUNT(status) AS cnt
    FROM tname
    WHERE status IN ('accepted','assigned')
    GROUP BY b.statusName
    HAVING (cnt > 1)) t

Answer 2

Its simple, replace group by by where

SELECT status, COUNT(status) AS cnt
 FROM tname 
 WHERE b.statusName IN ('completed','accepted')
 HAVING (cnt > 1)

Answer 3

从tname中选择COUNT（状态）AS cnt status =“已完成”或status =“已接受”