Using tsql greater than sign in CASE Expression

Question

(case [dbo].[YearsInService]([DateEngaged],getdate())
   when (0) then (0) 
   when (1) then (4) 
   when (2) then (8)
    when (3) then (12)
     when (4) then (32)         


        

Answer 1

You are using a Simple Case statement where logical expressions are not allowed. You need to use a Searched CASE expression. But in your case since you are using a function it will be bit costly to get the return value from the function for each expression.

Here is MSDN Link for both Simple Case and Searched CASE Syntax

I would suggest you to use a sub query with a Searched case as bellow.

select case when results = 0 then 0
            when results = 1 then 4
            ...
            when results >= 10 then 150
            else -1 end as CaseResults
from (select [dbo].[YearsInService]([DateEngaged],getdate()) results
      from yourTable
     ) Temp