Pinal Dave posted yesterday about how to solve the Fizz Buzz problem using T-SQL.
Definition of FizzBuzz Puzzle : Write a program that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”.
His solution works, but he is using procedural logic. Some of the biggest causes of performance problems in SQL Server are caused by application developers who try to use procedural logic instead of using the set-based logic that databases are meant for.
Here is how to solve the FizzBuzz problem using set-based logic in T-SQL:
WITH Numbers(Number) AS ( SELECT 1 UNION ALL SELECT Number + 1 FROM Numbers WHERE Number < 100 ) SELECT CASE WHEN Number % 3 = 0 AND Number % 5 = 0 THEN 'FizzBuzz' WHEN Number % 3 = 0 THEN 'Fizz' WHEN Number % 5 = 0 THEN 'Buzz' ELSE CONVERT(VARCHAR(3), Number) END FROM Numbers ORDER BY Number







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Nice
This reminds us how hard is is to keep your mind on SET BASED all the time.
Rob,
This doesn't seem to scale well.
When I change the where clause to "WHERE Number < 102", I get:
"The statement terminated. The maximum recursion 100 has been exhausted before statement completion."
Rob,
This also shows another thing. The CTE is recursive in nature. So what we really have here is an example of using recursion.
That would be because the default MAXRECURSION is 100. If you want to go above that, add OPTION(MAXRECURSION 102) after the ORDER BY clause. You can use 0 for unlimited, but be careful.
declare @num int,
@n1 int,
@n2 int
set @num = 1
while(@num < = 100)
begin
select @n1 = (@num%3)
select @n2 = (@num%5)
if (@n1 = 0)
if (@n1 = 0 and @n2 = 0)
Print ‘FizzBuzz’
else
Print ‘Fizz’
if (@n1 != 0 and @n2 = 0)
Print ‘Buzz’
else
if (@n1 != 0 and @n2 != 0)
Print @num
set @num = @num + 1
end
if (@n1 != 0 and @n2 != 0) not required though
Hi, how about the following for a fully set based solution…
create table #temp
(number int )
go
insert into #temp(number)
select top 100 row_number() OVER (ORDER BY [object_id]) from sys.columns;
select
number
, case
when number % 3 = 0 AND number % 5 = 0 then ‘fizzbuzz’
when number % 3 = 0 then ‘fizz’
when number % 5 = 0 then ‘buzz’
else ” end as test
from #temp;
drop table #temp;