Cross apply MSSQL operator equivalent in bigquery - sql-server

Question

is there an equivalent to cross apply in Sql server syntaxe or in bigquery syntaxe.
I need to write this query without the cross apply:
select *
from t1
cross apply (select top 1 col1,col2,col3
from t2
where col1 = t1.col1
and (col2 = '0' or col2 = t1.col2)
and (col3 = '0' or (col3 = left(t1.col3) and t1.col4 = 'fr'))
order by col2 desc, col3 desc)
t1 called 'Delivery' contains deliveries informations:
Delivery_ID,Delivery_ShipmentDate,Country_Code,address_ZipCode and the providerservice_id
t2 called 'ProviderService' contains informations about the providerservice:
Providerservice_id,DCountry_ID , DZone_Code as well as a numeric ProviderService_DeliveryTime.
So each Delivery_ID has a ProviderService_ID
And For the same Providerservice we could have several distinct ProviderService_DeliveryTime according to the other columns in this table(DCountry_ID , DZone_Code)
So the final query will be:
Select t1.Delivery_ShipmentDate,t2.ProviderService_DeliveryTime
from Delivery t1
cross apply (select top 1 ProviderService_DeliveryTime,DCountry_ID , DZone_Code
from ProviderService
where ProviderService_id = t1.ProviderService_id
And (DCountry_ID = '0' or DCountry_ID = t1.Country_Code)
And (DZone_Code = '0' or (DZone_Code = left(t1.address_ZipCode,2) and t1.Country_Code='FR'))
order by t2.DCountry_ID desc, t2.DZone_Code desc)sq
In fact I need first to write the same query in sql server syntaxe and then to write it in Bigquery because BigQuery don't recognize "cross apply" operator.
I tried to do it with row_number window function but it did not work:
with cte as (Select t1.Delivery_ShipmentDate,t2.ProviderService_DeliveryTime,row_number() over (partition by t2.providerservice_id order by t2.DCountry_ID desc, t2.DZone_Code desc) as num
from Delivery t1
inner join providerservice t2 on t1.providerservice_id = t2.providerservice_id
And (DCountry_ID = '0' or DCountry_ID = t1.Country_Code)
And (DZone_Code = '0' or (DZone_Code = left(t1.address_ZipCode,2) and t1.Country_Code='FR')))
select * from cte where num = 1
it works only when I filter by delivery_id:
with cte as (Select t1.Delivery_ShipmentDate,t2.ProviderService_DeliveryTime,row_number() over (partition by t2.providerservice_id order by t2.DCountry_ID desc, t2.DZone_Code desc) as num
from Delivery t1
inner join providerservice t2 on t1.providerservice_id = t2.providerservice_id
And (DCountry_ID = '0' or DCountry_ID = t1.Country_Code)
And (DZone_Code = '0' or (DZone_Code = left(t1.address_ZipCode,2) and t1.Country_Code='FR'))
where delivery_id = xxxx)
select * from cte where num = 1
Can any one help me please? Thanks!!

Answer 1

Below is for BigQuery Standard SQL
#standardSQL
SELECT * EXCEPT(pos)
FROM (
SELECT *
ROW_NUMBER() OVER(PARTITION BY TO_JSON_STRING(t1) ORDER BY t2.col2 DESC, t2.col3 DESC) pos
FROM t1 INNER JOIN t2
ON t2.col1 = t1.col1
AND (t2.col2 = '0' OR t2.col2 = t1.col2)
AND (t2.col3 = '0' OR (t2.col3 = left(t1.col3) AND t1.col4 = 'fr'))
)
WHERE pos = 1
I wish you gave us some data to play with - but having absence of it - above is just quick shot for you to try
I checked this approach (of implementing CROSS APPLY in BigQuery) against classic example with customers and orders tables and it worked

Answer 2

Would correlated subquery work the same as cross apply?
select *
from t1 , (select col1,col2,col3
from t2
where col1 = t1.col1
and (col2 = '0' or col2 = t1.col2)
and (col3 = '0' or (col3 = left(t1.col3) and t1.col4 = 'fr'))
order by col2 desc, col3 desc
limit 1)