将 sql 代码转换为 bigquery sql (eomonth)

Question

I want to split my monthly Values in daily values. The monthly value also split by the number of days of the month. I found a SQL query but I cant apply the query in Bigquery. How can I apply this query in BigQuery? Are there any options instead of eomonth?

with cte as

 (
select 
    targetdate, 
    eomonth(targetdate) enddate, 
    1.0 * units / day(eomonth(targetdate)) units
from targettable
union all
select dateadd(day, 1, targetdate), enddate, units 
from cte
where targetdate < enddate ) 

select targetdate, units from cte    
 
  
   

Thanks!

Answer 1

last_day is the Bigquery function equivalent of eomonth .

Bigquery's generate_date_array is a better solution than the recursive CTE in your example. Which is lucky as Bigquery does not support recursive CTEs.

Here's the answer:

with targettable as (
    SELECT date('2022-01-10') as targetdate, 31 as units
)
select days,
  last_day(targettable.targetdate) enddate,
  units / extract(day from days) as units
from targettable
cross join unnest(generate_date_array(targettable.targetdate, last_day(targettable.targetdate))) as days

The CTE is just for example data. generate_date_array gives an array which we unnest into rows. That happens in the from clause with a cross join as there is no join criteria, other than parameters to the function.

The "units" calculation is weird in the initial example. extract(day from days) gives the day of the month as an int64 , which is what the original does.

Answer 2

@Steven Ensslen

thank you!

date	store	cost
2022-01-10	a	3000
2022-01-10	b	2500

And finally the targettable should look like:

date	store	cost
2022-01-10	a	3000/sum day of months = 96,77
2022-02-10	a	3000/sum day of months
2022-03-10	a	3000/sum day of months
2022-04-10	a	3000/sum day of months
.... to last day of the month	a	3000/sum day of months
2022-01-10	b	2500/sum day of months
2022-02-10	b	2500/sum day of months
2022-03-10	b	2500/sum day of months
...	b	2500/sum day of months