Rounding a number up to the nearest 5

Question

Post reply

Rounding a number up to the nearest 5

smrobin

Ten Centuries

Points: 1003
More actions
September 13, 2013 at 2:08 pm

#283201

So I am attempting to mimic some legacy code on an old server at my work. It has a calculation to determine cost. What I need to do is round the number up to the nearest 5th.
For example:
1.0 -> 5 (everything less than 5 gets rounded to give)
5-> 5
5.75->5
8->10
11->15
86.5->90
so any number that has a 5 in it before the decimal - will stay rounded to 5. Example - 75.65 -> 75.
I have the following code:
declare @mon numeric(10,2)
set @mon = 86.5
select case when (round(@mon/5,0)*5) < 5 then 5
else (round(@mon/5,0)*5)
end
However - when I run it - 86.5 gets rounded to 85. I need it to round to 90.
Any suggestions?

Viewing 10 posts - 1 through 9 (of 9 total)

You must be logged in to reply to this topic. Login to reply

Sean Lange SSC Guru Points: 286590 More actions · Answer 1

You can use a tally for this pretty easily.

Here is the code to create a tally table view. This is super fast!!!

create View [dbo].[Tally] as

WITH

E1(N) AS (select 1 from (values (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))dt(n)),

E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows

E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max

cteTally(N) AS

(

SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4

)

select N from cteTally

GO

Now we just need to create your query. Please note that I used a cte here because we didn't have a table of data to work with.

with MyData (MyValue, Target) as

(

select 1.0, 5 union all

select 5, 5 union all

select 5.75, 5 union all

select 8, 10 union all

select 11, 15 union all

select 86.5, 90

)

select *

from MyData d

cross apply

(

select top 1 * from Tally

where N >= d.MyValue

and N % 5 = 0

order by N

) x

--EDIT--

You can read more about tally tables here. http://www.sqlservercentral.com/articles/62867/[/url]

_______________________________________________________________

Need help? Help us help you.

Read the article at http://www.sqlservercentral.com/articles/Best+Practices/61537/ for best practices on asking questions.

Need to split a string? Try Jeff Modens splitter http://www.sqlservercentral.com/articles/Tally+Table/72993/.

Cross Tabs and Pivots, Part 1 – Converting Rows to Columns - http://www.sqlservercentral.com/articles/T-SQL/63681/
Cross Tabs and Pivots, Part 2 - Dynamic Cross Tabs - http://www.sqlservercentral.com/articles/Crosstab/65048/
Understanding and Using APPLY (Part 1) - http://www.sqlservercentral.com/articles/APPLY/69953/
Understanding and Using APPLY (Part 2) - http://www.sqlservercentral.com/articles/APPLY/69954/

LinksUp SSCertifiable Points: 6526 More actions · Answer 2

Though not as cool a solution as Mr. Lange's tally table, this alternative is more math oriented than set oriented and is very fast. Plus you could easily turn this into a SP passing any value that you want to round to. NOTE: I borrowed Mr. Lange's cte to demo the solution. (Thank-you!)

;with MyData (MyValue, Target) as

(

select 0.5, 5 union all

select 1.0, 5 union all

select 2.0, 5 union all

select 5, 5 union all

select 5.75, 5 union all

select 8, 10 union all

select 11, 15 union all

select 50, 50 union all

select 50.5, 50 union all

select 50.75, 50 union all

select 51, 55 union all

select 54.99, 55 union all

select 86.5, 90

)

Select d.MyValue, d.Target,

case when d.MyValue % 5 < 1 then FLOOR(d.MyValue)

when d.MyValue % 5 < 3 then FLOOR ((d.MyValue + (5.0 / 2.0)) / 5) * 5.0 + 5.0

else FLOOR((d.MyValue + (5.0 / 2.0)) / 5) * 5.0

end as Result

from MyData d

The case statement was required because you are rounding UP to the nearest 5, not just to the nearest 5.

__________________________________________________________________________________________________________
How to Post to get the most: http://www.sqlservercentral.com/articles/Best+Practices/61537/

smrobin Ten Centuries Points: 1003 More actions · Answer 3

Thanks for the reply - the problem I have is that I don't always know what the number will be. I have the rules to which I apply to the numbers.

I was hoping to write a simple case statement to handle everything. Any suggestions on that?

LinksUp SSCertifiable Points: 6526 More actions · Answer 4

smrobin (9/13/2013)
Thanks for the reply - the problem I have is that I don't always know what the number will be. I have the rules to which I apply to the numbers.

Not sure who you are talking to!

Since you did not provide any dll or sample data, it had to be made up. Both solutions are generic in that you have to modify either of them to use your table and your column names. Also, both solutions are rounding up whatever is passed to them. There is no "fixed" value.

I was hoping to write a simple case statement to handle everything.

Is that not what I posted?

__________________________________________________________________________________________________________
How to Post to get the most: http://www.sqlservercentral.com/articles/Best+Practices/61537/

Sean Lange SSC Guru Points: 286590 More actions · Answer 5

Edited my code...but the edit was incorrect. 😀

_______________________________________________________________

Need help? Help us help you.

Read the article at http://www.sqlservercentral.com/articles/Best+Practices/61537/ for best practices on asking questions.

Need to split a string? Try Jeff Modens splitter http://www.sqlservercentral.com/articles/Tally+Table/72993/.

Cross Tabs and Pivots, Part 1 – Converting Rows to Columns - http://www.sqlservercentral.com/articles/T-SQL/63681/
Cross Tabs and Pivots, Part 2 - Dynamic Cross Tabs - http://www.sqlservercentral.com/articles/Crosstab/65048/
Understanding and Using APPLY (Part 1) - http://www.sqlservercentral.com/articles/APPLY/69953/
Understanding and Using APPLY (Part 2) - http://www.sqlservercentral.com/articles/APPLY/69954/

smrobin Ten Centuries Points: 1003 More actions · Answer 6

Thanks for the replies guy! I used your combined logic and got it to work! Thanks again - love this site!

Jeff Moden SSC Guru Points: 1004363 More actions · Answer 7

smrobin (9/16/2013)
Thanks for the replies guy! I used your combined logic and got it to work! Thanks again - love this site!

Two way street here, my friend. Please post what you ended up with. Thanks.

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

Don Halloran SSCertifiable Points: 5937 More actions · Answer 8

Don Halloran

SSCertifiable

Points: 5937

September 18, 2013 at 5:52 pm

#1651335

select ceiling(floor(@somevalue) / 5.0) * 5.0

LinksUp SSCertifiable Points: 6526 More actions · Answer 9

Don Halloran (9/18/2013)
select ceiling(floor(@somevalue) / 5.0) * 5.0

A MUCH better solution!

__________________________________________________________________________________________________________
How to Post to get the most: http://www.sqlservercentral.com/articles/Best+Practices/61537/