使用 sum 和 case 时的结果相同

Question

我有以下查询，但它产生相同的结果，结果应该不同

select 
COALESCE(Clinic,'total') as Clinic,
sum(Revenue/ND) as Revenue_ND,
sum(Revenue/Home_Care) as Revenue_Home_Care
from
(
   select
   businesses.label as Clinic,
   COUNT(CASE 
    WHEN appointment_types.name like '%initial%' and appointment_types.category IN (
        'National- Ex Phys- ND',
        'National- Physio -ND',
        'National- OT -ND',
        'National- Speech Pathology- ND',
        'SA/WA - Physiotherapy - ND',
        'SA/WA - Telehealth Physiotherapy - ND'
    ) then 1 ELSE 0 END) 
    as ND,
   COUNT(CASE 
    WHEN appointment_types.name like '%initial%' and appointment_types.category IN (
        'National- Zest',
        'National- OT -HCP',
        'National- Physio -HCP',
        'National- Physio -Remedy',
        'National-Physio-TUH',
        'National- Speech Pathology- HCP'
    ) then 1 ELSE 0 END)
    as Home_Care,
  sum(CASE 
    WHEN appointment_types.category is not null 
    then invoices.net_amount ELSE 0 END)
    as Revenue
FROM 
  individual_appointments
  INNER join appointment_types on
  appointment_types.id = individual_appointments.appointment_type_id
  inner join invoices on
  invoices.appointment_id = individual_appointments.id
  inner join businesses on
  businesses.id = individual_appointments.business_id
WHERE
  {{clinic}} 
  and {{date}}
group by 
  businesses.label
)x
group by 
  ROLLUP(Clinic);

结果：

 Clinic                   Revenue_ND             Revenue_Home_Care
 Marli                    51.33                    51.33
 Alexandria               94.21                    94.21
 total                    230.48                   230.48

它应该导致不同的列值。 你能告诉我错误在哪里以及正确的查询解决方案吗？

Answer 1

问题的原始版本被标记为 MySQL。

COUNT() 计算条件的非NULL 值的数量。在您的代码中，CASE 表达式返回1 或0。而且这些都不是NULL。

对于这种类型的计数，MySQL 有一个方便的快捷方式，不需要条件逻辑。您可以将布尔值相加：

SUM( appointment_types.name like '%initial%' and 
     appointment_types.category IN (
     'National- Ex Phys- ND',
     'National- Physio -ND',
     'National- OT -ND',
     'National- Speech Pathology- ND',
     'SA/WA - Physiotherapy - ND',
     'SA/WA - Telehealth Physiotherapy - ND'
    )) 

编辑：

在 SQL Server（和许多其他数据库）中，您需要一个显式的 CASE 表达式：

SUM(CASE WHEN appointment_types.name like '%initial%' and 
              appointment_types.category IN (
              'National- Ex Phys- ND',
              'National- Physio -ND',
              'National- OT -ND',
              'National- Speech Pathology- ND',
              'SA/WA - Physiotherapy - ND',
              'SA/WA - Telehealth Physiotherapy - ND'
              )
         THEN 1 ELSE 0
    END)