If you have developed some sort of applications using
Microsoft Access, then you are definitely familiar with “IIF” logical function.
In SQL Server, prior to SQL Server Denali we can use “CASE” instead of “IIF” as
this logical function was not available. But in SQL Server Denali CTP3, “IIF”
is available with same ease and functionality.
According to BOL”IIF is a shorthand way for writing a CASE statement. It
evaluates the Boolean expression passed as the first argument, and then returns
either of the other two arguments based on the result of the evaluation. That
is, the true_value is returned if the Boolean expression is true, and the
false_value is returned if the Boolean expression is false or unknown.
true_value and false_value can be of any type. The same rules that apply to the
CASE statement for Boolean expressions, null handling, and return types also
apply to IIF.
The fact that IIF is translated into CASE also has an impact on other aspects
of the behavior of this function. Since CASE statements can nested only up to
the level of 10, IIF statements can also be nested only up to the maximum level
of 10. Also, IIF is remoted to other servers as a semantically equivalent CASE
statement, with all the behaviors of a remoted CASE statement.”
Let’s try it with simple example.
(Only applicable for SQL Server Denali
CTP 3)
DECLARE @weather VARCHAR(50) = 'Rainy', -- Rain/Sunny
@umbrella BIT = 1 --1= Yes we have, 0=No
we don't have
--Single IIF
SELECT IIF(@weather ='Rainy','Oh! its raining','Sun is shinning..Enjoy')
--Multiple
IIF
SELECT IIF(
@weather = 'Rainy',IIF(
@umbrella = 1,'Its raining but you can
take umbrella with you'
,'Sun is shining..Enjoy')
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Read More about SQL Server 2012 (Code Name: Denali)
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Read More about SQL Server 2012 (Code Name: Denali)
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