如何在SQL連接中使用值的總和

Question

請幫我找到鏈接表中Service_times的總和。

CREATE TABLE incidents (incident_id int,date_logged datetime,usr_id int,dept_id int,item_id int, cust_id int) 

insert into incidents values 
('1001', '8/20/2016', '190', '3', '800', '10'), 
('1002', '8/21/2016', '111', '4', '810', '12'), 
('1003', '8/22/2016', '190', '3', '800', '10'), 
('1004', '8/23/2016', '111', '4', '822', '12') 


Create TABLE actions (act_id int, act_type varchar(50) , incident_id int, usr_id int ,date_actioned datetime, service_time money) 

Insert into actions VALUES 
('1', 'TRAVEL', 1001, 190, 8/20/2016, 20), 
('2', 'ASSIGN', 1001, 2, 8/21/2016, 1), 
('3', 'TRAVEL', 1001, 190 ,8/22/2016, 10), 
('4', 'REMOTE', 1001, 190, 8/23/2016, 30), 
('5', 'TRAVEL', 1002, 111, 8/21/2016, 40), 
('6', 'ASSIGN', 1002, 2, 8/22/2016 ,1), 
('7', 'REMOTE', 1002, 111, 8/23/2016, 30), 
('8', 'TRAVEL', 1002, 111, 8/24/2016, 60), 
('9', 'TRAVEL', 1003, 190, 8/22/2016, 45), 
('10', 'ASSIGN', 1003, 2, 8/23/2016 ,1), 
('11', 'REMOTE', 1003, 190 ,8/23/2016 ,10), 
('12', 'REMOTE', 1003, 190 ,8/23/2016 ,20), 
('13', 'ASSIGN', 1004, 2 ,8/23/2016 ,1), 
('14', 'TRAVEL', 1004, 111, 8/23/2016, 20), 
('15', 'TRAVEL', 1004, 111, 8/23/2016, 20), 
('16', 'REMOTE', 1004, 111, 8/23/2016, 20) 


CREATE TABLE inc_data (incident_id int,Rep1 char(1), Rep2 char(1), Rep3 char(1), Res1 char(1), Res2 char(1), Res3 char(1)) 

insert into inc_data values 
(1001, 'y', 'y', 'y', 'y', 'y', 'n'), 
(1002, 'n', 'n', 'n', 'n', 'n', 'n'), 
(1003, 'y', 'y', 'n', 'n', 'n', 'n'), 
(1004, 'y', 'y', 'y', 'y' , 'y', 'y') 

我的查詢：

SELECT i.usr_id, 
     COUNT(CASE WHEN inc_data.Rep3 = 'y' THEN 1 END) AS RespBreach, 
     COUNT(CASE WHEN inc_data.Res3 = 'y' THEN 1 END) AS ResBreach, 
     COUNT(i.incident_id)as CallCount, 
     (SELECT  ISNULL(SUM(A.service_time), 0) AS Expr1 
     FROM actions AS WHERE A.act_type= 'TRAVEL')) AS Travel_Time, 
     (SELECT  ISNULL(SUM(A.service_time), 0) AS Expr1 
     FROM actions AS WHERE A.act_type= 'REMOTE')) AS Remote_Time  
FROM incidents as i 
INNER JOIN inc_data ON i.incident_id= inc_data.incident_id 
INNER JOIN actions act1 on i.incident_id=act1.incident_id 
GROUP BY i.usr_id 

預期結果：

+--------+-----------+-------------+-------------+-----------+-----------+--+--+--+ 
| usr_id | Callcount | Travel_Time | Remote_Time | RepBreach | ResBreach | | | | 
+--------+-----------+-------------+-------------+-----------+-----------+--+--+--+ 
| 190 |   2 |   75 |   60 |   1 |   0 | | | | 
| 111 |   2 |   140 |   50 |   1 |   1 | | | | 
+--------+-----------+-------------+-------------+-----------+-----------+--+--+--+ 

Answer 1

無需相關子查詢計算遠程和旅行時間。隨着動作表的加入，您可以簡單地使用條件聚合。

此外，計數應該針對不同的incident_id，因爲關係是一對多關係。

SELECT i.usr_id, 
     COUNT(DISTINCT CASE WHEN inc_data.Rep3 = 'y' THEN 1 END) AS RespBreach, 
     COUNT(DISTINCT CASE WHEN inc_data.Res3 = 'y' THEN 1 END) AS ResBreach, 
     COUNT(DISTINCT i.incident_id) as CallCount, 
     SUM(CASE WHEN act1.act_type= 'TRAVEL' THEN ISNULL(act1.service_time, 0) ELSE 0 END) AS Travel_Time, 
     SUM(CASE WHEN act1.act_type= 'REMOTE' THEN ISNULL(act1.service_time, 0) ELSE 0 END) AS Remote_Time  
FROM incidents as i 
INNER JOIN inc_data ON i.incident_id= inc_data.incident_id 
INNER JOIN actions act1 on i.incident_id=act1.incident_id 
GROUP BY i.usr_id 

Sample Demo