CASE equivalent of a nested IIF statement

Question

Can anyone please decode the following nested IIF to a CASE statement in SQL.. I know IIF is allowed in SQL Server 2012 but I find it hard to get an easy grasp of a nested IIF l

Answer 1

This is old now, and there are other answers that already work, but for fun it is possible to write this as a functional expression without any CASE statements at all, like this:

char(65 + ceiling(ceiling(COALESCE(NULLIF(TABLE_A.Col_1, 0), TABLE_A.Col_2 + (2*TABLE_A.Col_3))) - .5 / 10000000000000))

There is a very small chance that the functional approach will perform noticeably better on large sets with good indexing.

Here's my proof-of-concept test script:

http://sqlfiddle.com/#!3/a95b3/2