SQL Server IIF vs CASE
问题 I recently came to know about the availability of IIF function in SQL Server 2012. I always use nested CASE in my queries. I want to know the exact purpose of the IIF statement and when should we prefer using IIF over CASE Statement in the query. I mostly use nested CASE in my queries. Thanks for all the inputs. 回答1: IIF is the same as CASE WHEN <Condition> THEN <true part> ELSE <false part> END . The query plan will be the same. It is, perhaps, "syntactical sugar" as initially implemented.