Remove all non numeric characters in sql SELECT - sql

Question

I want to remove all non-numeric characters when I call the query in SQL.
I have a function and in function, I do it so:
Declare #KeepValues as varchar(50)
Set #KeepValues = '%[^0-9]%'
While PatIndex(#KeepValues, #Temp) > 0
Set #Temp = Stuff(#Temp, PatIndex(#KeepValues, #Temp), 1, '')
But now I want to do it with query (select).
I tried so but this doesn't work
select substring(AdrTelefon1, PatIndex('%[^0-9]%', AdrTelefon1), 2000) from test
EDIT
I have it!
Select query to remove non-numeric characters
It does not work correctly
SELECT LEFT(SUBSTRING(AdrTelefon1, PATINDEX('%[0-9]%', AdrTelefon1), 8000),
PATINDEX('%[^0-9]%', SUBSTRING(AdrTelefon1, PATINDEX('%[0-9]%', AdrTelefon1), 8000) + 'X') -1) from test
I have 04532/97 and after this query, I have 04532 BUT I NEED 0453297

Answer 1

Some time ago I solved that problem using the below function
create function dbo.[fnrReplacetor](#strtext varchar(2000))
returns varchar(2000)
as
begin
declare #i int = 32, #rplc varchar(1) = '';
while #i < 256
begin
if (#i < 48 or #i > 57) and CHARINDEX(char(#i),#strtext) > 0
begin
--° #176 ~ 0 --¹ #185 ~ 1 --² #178 ~ 2 --³ #179 ~ 3
set #rplc = case #i
when 176 then '0'
when 185 then '1'
when 178 then '2'
when 179 then '3'
else '' end;
set #strtext = REPLACE(#strtext,CHAR(#i),#rplc);
end
set #i = #i + 1;
end
return #strtext;
end
GO
select dbo.[fnrReplacetor]('12345/97')
Note it ill also consider characters °,¹,²,³ numeric and replace then with 0,1,2,3.
I put it in a function to readly reuse it in my scenario I needed to fix many columns in many tables at once.
update t
set t.myColumn = dbo.[fnrReplacetor](tempdb.myColumn)
from test t
where tempdb.myColumn is not null
or just
select dbo.[fnrReplacetor](tempdb.myColumn) as [Only Digits]
from test t
where tempdb.myColumn is not null
Obs: this is not the fatest way but a thorough one.
Edit
A non UDF solution must be use REPLACE but since regex is not that great in SQL you can end doing something nasty like the below example:
declare #test as table (myColumn varchar(50))
insert into #test values ('123/45'),('123-4.5')
Select replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(myColumn,'a',''),'b',''),'c',''),'d',''),'e',''),'f',''),'g',''),'h',''),'i',''),'j',''),'k',''),'l',''),'m',''),'n',''),'o',''),'p',''),'q',''),'r',''),'s',''),'t',''),'u',''),'v',''),'w',''),'x',''),'y',''),'z',''),'A',''),'B',''),'C',''),'D',''),'E',''),'F',''),'G',''),'H',''),'I',''),'J',''),'K',''),'L',''),'M',''),'N',''),'O',''),'P',''),'Q',''),'R',''),'S',''),'T',''),'U',''),'V',''),'W',''),'X',''),'Y',''),'Z',''),'.',''),'-',''),'/','')
from #test

Answer 2

#Emma W.
I agree with the others... you actually should use a function for this. Here's a very high-performance function that will work for 2008 and above. It includes full documentation and usage examples.
As a bit of a sidebar, any function that contains the word BEGIN is either a slow, performance hogging, scalar function or mTFV (multi-statement Table Valued Function). Most savvy DBAs won't allow either but may not know the difference between those two and an iTVF (inline Table Valued Function), like the one below.
CREATE OR ALTER FUNCTION [dbo].[DigitsOnly]
/**********************************************************************************************************************
Purpose:
Given a VARCHAR(8000) or less string, return only the numeric digits from the string.
Programmer's Notes:
1. This is an iTVF (Inline Table Valued Function) that will be used as an iSF (Inline Scalar Function) in that it
returns a single value in the returned table and should normally be used in the FROM clause as with any other iTVF.
2. The main performance enhancement is using a WHERE clause calculation to prevent the relatively expensive XML PATH
concatentation of empty strings normally determined by a CASE statement in the XML "loop".
3. Another performance enhancement is not making this function a generic function that could handle a pattern. That
allows us to use all integer math to do the comparison using the high speed ASCII function convert characters to
their numeric equivalent. ASCII characters 48 through 57 are the digit characters of 0 through 9 in most languages.
4. Last but not least, added another of Eirikur's later optimizations using 0x7FFF which he says is a "simple trick to
shift all the negative values to the top of the range so a single operator can be applied, which is a lot less
expensive than using between.
-----------------------------------------------------------------------------------------------------------------------
Kudos:
1. Hats off to Eirikur Eiriksson for the ASCII conversion idea and for the reminders that dedicated functions will
always be faster than generic functions and that integer math beats the tar out of character comparisons that use
LIKE or PATINDEX.
2. Hats off to all of the good people that submitted and tested their code on the following thread. It's this type of
participation and interest that makes code better. You've just gotta love this commmunity.
http://www.sqlservercentral.com/Forums/Topic1585850-391-2.aspx#bm1629360
-----------------------------------------------------------------------------------------------------------------------
Usage Example:
--===== CROSS APPLY example
SELECT ca.DigitsOnly
FROM dbo.SomeTable st
CROSS APPLY dbo.DigitsOnly(st.SomeVarcharCol) ca
;
-----------------------------------------------------------------------------------------------------------------------
Test Harness:
--===== Create the 1 Million row test table
DROP TABLE IF EXISTS #TestTable
;
SELECT TOP 1000000
Txt = ISNULL(CONVERT(VARCHAR(36),NEWID()),'')
INTO #TestTable
FROM sys.all_columns ac1
CROSS JOIN sys.all_columns ac2
;
ALTER TABLE #TestTable
ADD PRIMARY KEY CLUSTERED (Txt)
;
GO
--===== CROSS APPLY example.
-- This takes ~ 1 second to execute.
DROP TABLE IF EXISTS #Results;
SELECT tt.Txt, ca.DigitsOnly
INTO #Results
FROM #TestTable tt
CROSS APPLY dbo.DigitsOnly(Txt) ca
;
GO
--===== Return the results for manual verification.
SELECT * FROM #Results
;
-----------------------------------------------------------------------------------------------------------------------
Revision History:
Rev 00 - 28 Oct 2014 - Eirikur Eiriksson
- Initial creation and unit/performance tests.
Rev 01 - 29 Oct 2014 - Jeff Moden
- Performance enhancement and unit/performance tests.
Rev 02 - 30 Oct 2014 - Eirikur Eiriksson
- Additional Performance enhancement
Rev 03 - 01 Sep 2014 - Jeff Moden
- Formalize the code and add the documenation that appears in the flower box of this code.
***********************************************************************************************************************/
--======= Declare the I/O for this function
(#pString VARCHAR(8000))
RETURNS TABLE WITH SCHEMABINDING AS
RETURN WITH
E1(N) AS (SELECT N FROM (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) AS E0(N))
,Tally(N) AS (SELECT TOP (LEN(#pString)) (ROW_NUMBER() OVER (ORDER BY (SELECT 1))) FROM E1 a,E1 b,E1 c,E1 d)
SELECT DigitsOnly =
(
SELECT SUBSTRING(#pString,N,1)
FROM Tally
WHERE ((ASCII(SUBSTRING(#pString,N,1)) - 48) & 0x7FFF) < 10
FOR XML PATH('')
)
;
GO
If you're really up against a wall and cannot use a function of any type because of "Rules" that have no exceptions (a really bad idea), then post back and we can show you how to convert it into inline code with a little help from you.
Whatever you do, don't use a WHILE loop for this task... it'll kill you performance and resource usage wise.