Combined Function Usage Cases
Case 1: Combine Aggregation Functions and Conditional Functions
Perform sum aggregation only when a certain condition is met.
The common approach requires pulling an additional branch with a filter and then stitching it back to the original logic. The combined formula below reduces steps and improves accuracy.
Example: sum + case when
sum(
case when [Route Level] = 'T1'
then [Returned Bottle Boxes]
else 0 end)
over(partition by [End-to-End Route], [Accounting Period], [Actual Route], [Whole Course Route])

Case 2: Cross-Row Assignment with first_value
- Create a field [Sort] = case when [Route Level] = 'T1' then 1 else 2 end.

- first_value([T1 Level Returned Bottle Boxes]) over(partition by [End-to-End Route], [Accounting Period], [Whole Course Route] order by [Sort])
Note: Row 5 in the screenshot is a WS segment. Its original returned bottle box count is 20, but it needs to take the volume from the T1 segment.

Extension: Combine Case 1 and Case 2
first_value(
sum(
case when [Route Level] = 'T1'
then [Returned Bottle Boxes]
else 0 end)
over(partition by [End-to-End Route], [Accounting Period], [Actual Route], [Whole Course Route])
)
over(partition by [End-to-End Route], [Accounting Period], [Whole Course Route] order by [Sort])
