SQL - 创建具有不同计数的另一列的列

Question

我正在尝试在我的 SQl 表中添加 3 列。

第 1 列：Total_Hours_Overall

我希望此列汇总每个 sequence_ID 的总小时数

第 2 列：Total_No_Codes

我希望此列是“客户”列中不同值的计数。

第 3 列：客户总数

我希望此列是 'Client' 列中的不同值的计数，其中 'Job_Type' 列等于 'Client'

下面是我目前拥有的表的 sn-p。有超过 800 个唯一的 sequence_ID，每个 ID 有多行。我希望上面的计算列显示每一行的值。

Sequence_ID |Date_European  |Hours  |Month  |Day    |Year   |Day_of_Week    |Client_Number  |Client         |Job_No |Job_Type
1001        |01/09/2017     |7.3    |9      |1      |2017   |Friday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE
1001        |04/09/2017     |7.3    |9      |4      |2017   |Monday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE
1001        |09/08/2017     |2      |8      |9      |2017   |Wednesday      |1              |Admin          |A1     |Non-Billable
1001        |24/08/2017     |1.3    |8      |24     |2017   |Thursday       |2              |Client1        |A2     |Client
1001        |28/08/2017     |2.3    |8      |28     |2017   |Monday         |2              |Client1        |A2     |Client
1001        |16/08/2017     |0.5    |8      |16     |2017   |Wednesday      |3              |Client2        |A3     |Client
1001        |16/08/2017     |1      |8      |16     |2017   |Wednesday      |2              |Client1        |A2     |Client
1001        |18/08/2017     |3      |8      |18     |2017   |Friday         |3              |Client2        |A3     |Client
1001        |22/08/2017     |0.7    |8      |22     |2017   |Tuesday        |4              |Client3        |A4     |Client
1001        |16/08/2017     |7.3    |8      |16     |2017   |Wednesday      |5              |Client4        |A5     |Client
1001        |18/08/2017     |1.3    |8      |18     |2017   |Friday         |5              |Client4        |A5     |Client
1001        |21/08/2017     |1      |8      |21     |2017   |Monday         |5              |Client4        |A5     |Client
1001        |12/09/2017     |0.6    |9      |12     |2017   |Tuesday        |5              |Client4        |A5     |Client
1002        |01/09/2017     |7.3    |9      |1      |2017   |Friday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE
1002        |04/09/2017     |7.3    |9      |4      |2017   |Monday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE
1002        |09/08/2017     |2      |8      |9      |2017   |Wednesday      |1              |Admin          |A1     |Non-Billable
1002        |24/08/2017     |1.3    |8      |24     |2017   |Thursday       |4              |Client3        |A4     |Client
1002        |28/08/2017     |2.3    |8      |28     |2017   |Monday         |5              |Client4        |A5     |Client

以下是我希望我的表格的外观。

Sequence_ID |Date_European  |Hours  |Month  |Day    |Year   |Day_of_Week    |Client_Number  |Client         |Job_No |Job_Type       |Total_Hours_Overall    |Total_No_Codes |Total Clients
1001        |01/09/2017     |7.3    |9      |1      |2017   |Friday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE   |35.6                   |6              |4
1001        |04/09/2017     |7.3    |9      |4      |2017   |Monday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE   |35.6                   |6              |4
1001        |09/08/2017     |2      |8      |9      |2017   |Wednesday      |1              |Admin          |A1     |Non-Billable   |35.6                   |6              |4
1001        |24/08/2017     |1.3    |8      |24     |2017   |Thursday       |2              |Client1        |A2     |Client         |35.6                   |6              |4
1001        |28/08/2017     |2.3    |8      |28     |2017   |Monday         |2              |Client1        |A2     |Client         |35.6                   |6              |4
1001        |16/08/2017     |0.5    |8      |16     |2017   |Wednesday      |3              |Client2        |A3     |Client         |35.6                   |6              |4
1001        |16/08/2017     |1      |8      |16     |2017   |Wednesday      |2              |Client1        |A2     |Client         |35.6                   |6              |4
1001        |18/08/2017     |3      |8      |18     |2017   |Friday         |3              |Client2        |A3     |Client         |35.6                   |6              |4
1001        |22/08/2017     |0.7    |8      |22     |2017   |Tuesday        |4              |Client3        |A4     |Client         |35.6                   |6              |4
1001        |16/08/2017     |7.3    |8      |16     |2017   |Wednesday      |5              |Client4        |A5     |Client         |35.6                   |6              |4
1001        |18/08/2017     |1.3    |8      |18     |2017   |Friday         |5              |Client4        |A5     |Client         |35.6                   |6              |4
1001        |21/08/2017     |1      |8      |21     |2017   |Monday         |5              |Client4        |A5     |Client         |35.6                   |6              |4
1001        |12/09/2017     |0.6    |9      |12     |2017   |Tuesday        |5              |Client4        |A5     |Client         |35.6                   |6              |4
1002        |01/09/2017     |7.3    |9      |1      |2017   |Friday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE   |20.2                   |2              |2
1002        |04/09/2017     |7.3    |9      |4      |2017   |Monday         |0              |ANNUAL LEAVE   |0      |ANNUAL LEAVE   |20.2                   |2              |2
1002        |09/08/2017     |2      |8      |9      |2017   |Wednesday      |1              |Admin          |A1     |Non-Billable   |20.2                   |2              |2
1002        |24/08/2017     |1.3    |8      |24     |2017   |Thursday       |4              |Client3        |A4     |Client         |20.2                   |2              |2
1002        |28/08/2017     |2.3    |8      |28     |2017   |Monday         |5              |Client4        |A5     |Client         |20.2                   |2              |2

我尝试过（但失败了）很多方法。我认为需要使用子查询，但我似乎无法正确获取格式。

另一个我很难理解生成所需格式的问题是 count 函数，因为我知道这需要 group by 子句，但我现在想将所有行保留在我的表中。

我想我想太多了，所以任何帮助都将不胜感激。 在此先感谢

Answer 1

你可以使用窗口函数：

select t.*, sum(hours) over (partition by sequence_id) as sum_hours,
       max(codes_seqnum) over (partition by sequence_id) as num_codes,
       max(clients_seqnum) over (partition by sequence_id) as num_clients
from (select t.*,
             dense_rank() over (partition by sequence_id order by client) as codes_seqnum,
             dense_rank() over (partition by sequence_id, job_type order by (case when job_type = 'Client' then client end)) as client_seqnum
      from t
     ) t;

COUNT(DISTINCT) 在 SQL Server 中使用窗口函数实际上很棘手。以上基本有效，但如果没有客户端，它不会返回0。在结果中只使用JOIN 可能会更好：

select t.*, tt.sum_hours, tt.num_codes, tt.num_clients
from t join
     (select sequence_id, sum(hours) as sum_hours,
             count(distinct client) as num_codes,
             count(distinct case when job_type = 'Client' then client end) as num_clients
      from t
      group by sequence_id
     ) tt
     on tt.sequence_id = t.sequence_id;