title: Any Benefit To Combining or Splitting Conditions in CASE Statement?
body: <p>I have the following CASE statement in my SELECT:</p>
  <pre><code>CASE
      -- Populated, US or Canadian Formatted and Confirmed; Return Zip Untouched
      WHEN ( ( uc.[Zip] IS NOT NULL OR uc.[Zip] &lt;&gt; '' ) AND EXISTS( SELECT [Zip] FROM [ULTRA].[dbo].[CityStateInfo] WHERE ( (LEN(uc.[Zip]) = 5 OR LEN(uc.[Zip]) = 10) AND [Zip] = LEFT(uc.[Zip], 5) ) OR ( LEN(uc.[Zip]) = 7 AND [Zip] = uc.[Zip] ) ) )
          THEN uc.[Zip]   -- Data Confirmed, Return Zip Untouched
  
      -- Populated but not found above; Attempt to determine from City, State, Country
      WHEN ( uc.[Zip] IS NOT NULL OR uc.[Zip] &lt;&gt; '') AND EXISTS( SELECT [Zip] FROM [ULTRA].[dbo].[fn_LocationInfo](0, uc.[cleanCity], uc.[State], NULL, uc.[Country]) )
          THEN ( SELECT [Zip] FROM [ULTRA].[dbo].[fn_LocationInfo](0, uc.[cleanCity], uc.[State], NULL, uc.[Country]) )  -- Match Found; Return Match
  
      -- Not Populated; Attempt to determine from City, State, Country
      WHEN ( uc.[Zip] IS NULL OR uc.[Zip] = '')  AND EXISTS( SELECT [Zip] FROM [ULTRA].[dbo].[fn_LocationInfo](0, uc.[cleanCity], uc.[State], NULL, uc.[Country]) )
          THEN ( SELECT [Zip] FROM [ULTRA].[dbo].[fn_LocationInfo](0, uc.[cleanCity], uc.[State], NULL, uc.[Country]) )  -- Match Found; Return Match
  
      -- No Match Found
      ELSE uc.[Zip]
  END AS [Zip]
  </code></pre>
  <p>The middle two WHEN conditions are ultimately doing the exact same thing.  Is there any benefit to combining or leaving them separate?  I have them separate now just to make it easier to track my thought process</p>