使用 Big Query SQL 我可以实现以下减法（减去两行值并将其替换为该值）？

Question

application	buildingid	dashboarding_tag	value
Abacus	BLD01	Heating_System_Energy_Consumption	3000.00
Abacus	BLD02	Heating_System_Energy_Consumption	1000.00
Abacus	BLD04	Heating_System_Energy_Consumption	1000.00
Abacus	BLD05	Heating_System_Energy_Consumption	500.00
Abacus	BLD02	MVHR_Energy_Consumption	300.00
Abacus	BLD03	MVHR_Energy_Consumption	900.00
Abacus	BLD04	MVHR_Energy_Consumption	50.00
Abacus	BLD05	MVHR_Energy_Consumption	80.00
Abacus	BLD06	MVHR_Energy_Consumption	200.00
Forell	BLD07	Heating_System_Energy_Consumption	0.00
Forell	BLD08	Heating_System_Energy_Consumption	50.00
Forell	BLD09	Heating_System_Energy_Consumption	-5.00
Forell	BLD10	Heating_System_Energy_Consumption	-30.00

到

application	buildingid	dashboarding_tag	value
Abacus	BLD01	Heating_System_Energy_Consumption	3000.00
Abacus	BLD02	Heating_System_Energy_Consumption	700.00
Abacus	BLD04	Heating_System_Energy_Consumption	950.00
Abacus	BLD05	Heating_System_Energy_Consumption	420.00
Abacus	BLD02	MVHR_Energy_Consumption	300.00
Abacus	BLD03	MVHR_Energy_Consumption	900.00
Abacus	BLD04	MVHR_Energy_Consumption	50.00
Abacus	BLD05	MVHR_Energy_Consumption	80.00
Abacus	BLD06	MVHR_Energy_Consumption	200.00
Forell	BLD07	Heating_System_Energy_Consumption	0.00
Forell	BLD08	Heating_System_Energy_Consumption	50.00
Forell	BLD09	Heating_System_Energy_Consumption	-5.00
Forell	BLD10	Heating_System_Energy_Consumption	-30.00

请注意第 2、3 和 4 行中的值如何根据第 5、7、8 行中的值在 table 2 上发生变化。

逻辑是，如果应用程序是 Abacus，则始终替换 Heating_System_Energy_Consumption 的值，这样：

Heating_System_Energy_Consumption=Heating_System_Energy_Consumption-MVHR_Energy_Consumption 每栋建筑

Answer 1

考虑以下方法

select * except(value), 
  if(dashboarding_tag = 'Heating_System_Energy_Consumption', 
    value - sum(if(dashboarding_tag = 'MVHR_Energy_Consumption', value, 0)) over(partition by application, buildingid), 
  value) as value
from your_table

如果应用于您问题中的示例数据 - 输出为

使用 Big Query SQL 我可以实现以下减法（减去两行值并将其替换为该值）？

Using Big Query SQL I can I achieve the following subtraction ( subtract two row values and replace it with that value )?

sql

replace

subtraction

google-bigquery