Trimming special characters

Question

Trimming special characters

ImYourDBA

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Points: 5654
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December 20, 2012 at 10:11 am

#393821

One of our developers created this UDF to trim out special characters...is there a better way to do this?
ALTER FUNCTION [dbo].[UDF_TrimSpecialCharacter]
(
-- Add the parameters for the function here
@String varchar(100)
)
RETURNS VARCHAR(100)
AS
BEGIN
RETURN replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(@String,'-',''),',',''),'_',''),' ',''),'*',''),'.',''),'/',''),'\',''),'(',''),')',''),'#',''),':',''),';',''),'@',''),'~',''),'&','')
END
Owner & Principal SQL Server Consultant
Im Your DBA, Inc.
https://www.imyourdba.com/

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Jeff Moden SSC Guru Points: 1004356 More actions · Answer 1

SQLJocky (12/20/2012)
One of our developers created this UDF to trim out special characters...is there a better way to do this?
ALTER FUNCTION [dbo].[UDF_TrimSpecialCharacter]
(
-- Add the parameters for the function here
@String varchar(100)
)
RETURNS VARCHAR(100)
AS
BEGIN
RETURN replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(@String,'-',''),',',''),'_',''),' ',''),'*',''),'.',''),'/',''),'\',''),'(',''),')',''),'#',''),':',''),';',''),'@',''),'~',''),'&','')
END

Only slightly. The nested replaces are incredibly fast and, short of a CLR function, is probably the fastest method. The only other speed enhancement I can see is that it should be converted to an inline table valued function even though it returns a scalar value. To be sure, converting to an inline table valued function that does this can increase the speed of the function by 2 to 7 times. Please see the following article on that...

http://www.sqlservercentral.com/articles/T-SQL/91724/

From a functionality standpoint, I'd make @String a VARCHAR(8000) instead of VARCHAR(100).

--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)

ImYourDBA SSCertifiable Points: 5654 More actions · Answer 2

Thanks Jeff...that makes a lot of sense! 😀

Owner & Principal SQL Server Consultant
Im Your DBA, Inc.
https://www.imyourdba.com/

Jeff Moden SSC Guru Points: 1004356 More actions · Answer 3

SQLJocky (12/20/2012)
Thanks Jeff...that makes a lot of sense! 😀

Thanks for the feedback. Don't just take my word for it, though. Test it. Make sure. 🙂

--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)

ImYourDBA SSCertifiable Points: 5654 More actions · Answer 4

Yes. I passed on the recommendation with an example to the developer and told him to test it out. 🙂

Owner & Principal SQL Server Consultant
Im Your DBA, Inc.
https://www.imyourdba.com/

Dwain Camps SSC Guru Points: 86948 More actions · Answer 5

Jeff Moden (12/20/2012)
SQLJocky (12/20/2012)
One of our developers created this UDF to trim out special characters...is there a better way to do this?
ALTER FUNCTION [dbo].[UDF_TrimSpecialCharacter]
(
-- Add the parameters for the function here
@String varchar(100)
)
RETURNS VARCHAR(100)
AS
BEGIN
RETURN replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(@String,'-',''),',',''),'_',''),' ',''),'*',''),'.',''),'/',''),'\',''),'(',''),')',''),'#',''),':',''),';',''),'@',''),'~',''),'&','')
END
Only slightly. The nested replaces are incredibly fast and, short of a CLR function, is probably the fastest method. The only other speed enhancement I can see is that it should be converted to an inline table valued function even though it returns a scalar value. To be sure, converting to an inline table valued function that does this can increase the speed of the function by 2 to 7 times. Please see the following article on that...
http://www.sqlservercentral.com/articles/T-SQL/91724/
From a functionality standpoint, I'd make @String a VARCHAR(8000) instead of VARCHAR(100).

Using a binary collation might help also.

My mantra: No loops! No CURSORs! No RBAR! Hoo-uh![/I]
My thought question: Have you ever been told that your query runs too fast?

My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.

Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St