計算計數，然后計算總計數MySql的總和

Question

我的查詢

$sql = 'SELECT status FROM tablename';

結果

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

現在我可以找到每個狀態的總數

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

這將給

---

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

我如何只completed和已accepted計數？

Answer 1

將條件放在sum（）函數中時，這稱為條件求和：

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

或者，您可以使用where首先過濾子查詢：

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

其操作簡單，取代group by由where

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

Answer 3

從tname中選擇COUNT（狀態）AS cnt status =“已完成”或status =“已接受”