IT:AD:SQL Server:HowTo:SQL:Functions/Flow Control

Below are some examples of each type of flow control.

Simpler/than/CASE/WHEN/etc, the syntax is just IF (condition) … ELSE … :

DECLARE @compareprice money, @cost money 

EXECUTE Production.uspGetList '%Bikes%', 700, 
@compareprice OUT, 
@cost OUTPUT

IF @cost <= @compareprice 
    BEGIN
        PRINT 'Something'
    END
ELSE
    -- No wrapping with Begin/End required if only one one line:
    PRINT 'Something else'

BEGIN/END statements can be nested¹⁾.

That said, most times, people are simply looking for:

ISNull(sum(Amount),0)

And no…there is no IIF… or ternary ? statement in SQL Server (in 2010). Use CASE.

For more complex branching, use CASE:

CASE Committee 
WHEN 'Foo' THEN 'Y'
WHEN 'Bar' THEN 'Y'
ELSE ''
END As Committee

GOTO You can use GOTO statements to jump around if you want:

--Define the label: 
label : 

--Alter the execution:
GOTO label

Link: http://msdn.microsoft.com/en-us/library/ms180188.aspx