2 case statements which are linked

Question

I am relatively new in SQL coding and have a question regarding case statements.

What I want to achieve: I want to create a query being used for calculating correct obso

Answer 1

A column alias is not permitted in the FROM, WHERE, GROUP BY, or HAVING clauses. You can use a subquery or CTE, but SQL Server supports lateral joins via the APPLY keyword. This can be quite useful for introducing a column alias:

select o.Material, o.Plnt, v.[Inventory Reach],
       (case when v.[Inventory Reach] > 9
             then 1
             else 0.9
        end) as [Devaluation Class]
from [BAAS_PowerBI].[dbo].[Obs] o cross apply
     (values (case when o.[calculate 5-year demand] = 0
                   then 9.01
                   when o.[BAAS SO GI (601) 36] = 0
                   then 9.01
                   when o.[MS] in ('BI', 'BO')
                   then (o.[Stock all SP WH] / (o.[calculate 5-year demand] / 5))
                   when o.[MS] = 'BO'
                   then (o.[Stock all SP WH] / o.[BAAS SO GI (601) 36])
                   when o.[MS] ='BI'
                   then 0
                  else 9.01
              end
             )
     ) values([Inventory Reach])