Question

所以我一直在看这个，我似乎无法弄明白。

我有一个包含以下格式和示例数据的mysql表：

ID, Customer, Time, Error Code, Duration

1,Test1,00:12:00,400,120
2,Test2,00:14:00,404,60
3,Test1,00:15:00,404,120
4,Test2,00:17:00,503,120
5,Test1,00:19:00,400,60
6,Test1,00:20:00,400,60
7,Test2,00:21:00,503,60

我需要结果包含客户名称，每个客户名称的总行数，每个客户的错误代码，然后是每个客户的错误数量，然后将持续时间相加。因此，对于上述结果，我希望得到：

Test1, 4, 400, 3, 360
Test1, 4, 404, 1, 360
Test2, 2, 404, 1, 240
Test2, 2, 503, 2, 240

我遇到的问题是当我按错误代码分组时，行数的计数和持续时间的总和也按错误代码分组。我需要客户的总行数和持续时间，而不是每个错误代码的客户总行数和持续时间。

如果我需要包含任何其他内容，或者我可能非常混淆，请告诉我。

提前感谢您的所有帮助！

Answer 1

首先，您需要分组来获取计算列

 SELECT Customer, COUNT(*) as total_count, SUM(duration) as total_duration
 FROM yourTable
 GROUP BY  Customer

和

 SELECT Customer, Error, COUNT(*) as error_count
 FROM yourTable
 GROUP BY  Customer, Error

然后加入你的表

SELECT t1.Customer, 
       t2.total_count, 
       t1.error, 
       t3.error_count, 
       t2.total_duration
FROM yourTable as t1
JOIN (
     SELECT Customer, COUNT(*) as total_count, SUM(duration) as total_duration
     FROM yourTable
     GROUP BY  Customer
     ) as t2
  ON t1.Customer = t2.Customer
JOIN (
     SELECT Customer, Error, COUNT(*) as error_count
     FROM yourTable
     GROUP BY  Customer, Error
) as t3
 ON t1.Customer = t3.Customer
AND t1.Error = t3.Error
GROUP BY t1.Customer
       , t1.Error

Answer 2

您可以在子选择中使用连接与客户的总和您可以在子选择中使用连接，并使用客户总和

select a.customer, a.error, t.num_row, t.duration 
from my_table   a
inner join ( 
    select  customer, count(*) as num_row, sum(duration) duration 
    from my_table 
    group by customer 
  ) t on t.customer  = a.customer

按mysql中的列计算总行数和分组数

2 个答案: