Oracle SQL - 计算每月的作业数

Question

我正在统计每个月某个类型的工作 (G012) 出现的总次数，每个区域的 status_code 为“5200”。

我目前的代码是：

select area.area_name, count(area.area_name)
from area
inner join central_site on central_site.area_code = area.area_code
inner join job on job.site_code = central_site.site_code
inner join job_type on job.job_type_key = job_type.job_type_key
inner join job_status_log on job.job_number = job_status_log.job_number
where job_type.job_type_key = 'G012' and job_status_log.status_code = '5200'
group by area.area_name
order by area.area_name

我不确定如何计算，以便每个月都属于不同的类别 - 但我想最终得到的是：

Area             April     May     June    July    August    September    October
North Ward         2        5        3       2        7         4            3
South Ward         2        3        4       4        6         4            4

Answer 1

基本上您还必须按月份对数据进行分组：

select area.area_name,  EXTRACT(MONTH FROM job.actual_start_date) mon,  count(area.area_name)
from area
inner join central_site on central_site.area_code = area.area_code
inner join job on job.site_code = central_site.site_code
inner join job_type_key on job.job_type_key = job_type.job_type_key
inner join job_status_log on job.job_number = job_status_log.job_number
where job_type.job_type_key = 'G012' and job_status_log.status_code = '5200'
group by area.area_name,  EXTRACT(MONTH FROM job.actual_start_date)
order by area.area_name

您也可以使用TO_CHAR(job.actual_start_date, 'Month') 代替EXTRACT(MONTH FROM job.actual_start_date) 作为名称而不是数字。

要获得所需的输出（将月份作为列而不是行），您可以使用数据透视：

SELECT *
  FROM (select area.area_name,  EXTRACT(MONTH FROM job.actual_start_date) mon
          from area
         inner join central_site on central_site.area_code = area.area_code
         inner join job on job.site_code = central_site.site_code
         inner join job_type_key on job.job_type_key = job_type.job_type_key
         inner join job_status_log on job.job_number = job_status_log.job_number
         where job_type.job_type_key = 'G012' and job_status_log.status_code = '5200')
PIVOT (
  COUNT(*)
  FOR mon IN (1 AS January, 2 AS February, 3 AS March, 4 AS April, 5 AS May, 6 AS June, 7 AS July, 8 AS August, 9 AS September, 10 AS October, 11 AS November, 12 AS December)
)

要按年份分隔数据，只需在现在有EXTRACT(MONTH FROM job.actual_start_date) 的任何地方添加一个EXTRACT(YEAR FROM job.actual_start_date) 列。