Select query to remove non-numeric characters

I've got dirty data in a column with variable alpha length. I just want to strip out anything that is not 0-9.

I do not want to run a function or proc. I have a script that is similar that just grabs the numeric value after text, it looks like this:

Update TableName
set ColumntoUpdate=cast(replace(Columnofdirtydata,'Alpha #','') as int)
where Columnofdirtydata like 'Alpha #%'
And ColumntoUpdate is Null

I thought it would work pretty good until I found that some of the data fields I thought would just be in the format Alpha # 12345789 are not.

Examples of data that needs to be stripped

AB ABCDE # 123
ABCDE# 123
AB: ABC# 123

I just want the 123. It is true that all data fields do have the # prior to the number.

I tried substring and PatIndex, but I'm not quite getting the syntax correct or something. Anyone have any advice on the best way to address this?

See this blog post on extracting numbers from strings in SQL Server. Below is a sample using a string in your example:

DECLARE @textval NVARCHAR(30)
SET @textval = 'AB ABCDE # 123'

SELECT LEFT(SUBSTRING(@textval, PATINDEX('%[0-9.-]%', @textval), 8000),
           PATINDEX('%[^0-9.-]%', SUBSTRING(@textval, PATINDEX('%[0-9.-]%', @textval), 8000) + 'X') -1)

You can use stuff and patindex.

stuff(Col, 1, patindex('%[0-9]%', Col)-1, '')

SQL Fiddle

This works well for me:

CREATE FUNCTION [dbo].[StripNonNumerics]
(
  @Temp varchar(255)
)
RETURNS varchar(255)
AS
Begin

    Declare @KeepValues as varchar(50)
    Set @KeepValues = '%[^0-9]%'
    While PatIndex(@KeepValues, @Temp) > 0
        Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, '')

    Return @Temp
End

Then call the function like so to see the original something next to the sanitized something:

SELECT Something, dbo.StripNonNumerics(Something) FROM TableA

Here is an elegant solution if your server supports the TRANSLATE function (on sql server it's available on sql server 2017+ and also sql azure).

First, it replaces any non numeric characters with a @ character. Then, it removes all @ characters. You may need to add additional characters that you know may be present in the second parameter of the TRANSLATE call.

select REPLACE(TRANSLATE([Col], 'abcdefghijklmnopqrstuvwxyz+()- ,#+', '@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@'), '@', '')

In case if there are some characters possible between digits (e.g. thousands separators), you may try following:

declare @table table (DirtyCol varchar(100))
insert into @table values
	('AB ABCDE # 123')
	,('ABCDE# 123')
	,('AB: ABC# 123')
	,('AB#')
	,('AB # 1 000 000')
	,('AB # 1`234`567')
	,('AB # (9)(876)(543)')

;with tally as (select top (100) N=row_number() over (order by @@spid) from sys.all_columns),
data as (
	select DirtyCol, Col
	from @table
		cross apply (
			select (select C + ''
			from (select N, substring(DirtyCol, N, 1) C from tally where N<=datalength(DirtyCol)) [1]
			where C between '0' and '9'
			order by N
			for xml path(''))
		) p (Col)
	where p.Col is not NULL
)
select DirtyCol, cast(Col as int) IntCol
from data

Output is:

DirtyCol              IntCol
--------------------- -------
AB ABCDE # 123        123
ABCDE# 123            123
AB: ABC# 123          123
AB # 1 000 000        1000000
AB # 1`234`567        1234567
AB # (9)(876)(543)    9876543

For update, add ColToUpdate to select list of the data cte:

;with num as (...),
data as (
	select ColToUpdate, /*DirtyCol, */Col
	from ...
)
update data
set ColToUpdate = cast(Col as int)

CREATE FUNCTION FN_RemoveNonNumeric (@Input NVARCHAR(512))
RETURNS NVARCHAR(512)
AS
BEGIN
DECLARE @Trimmed NVARCHAR(512)

SELECT @Trimmed = @Input

WHILE PATINDEX('%[^0-9]%', @Trimmed) > 0
	SELECT @Trimmed = REPLACE(@Trimmed, SUBSTRING(@Trimmed, PATINDEX('%[^0-9]%', @Trimmed), 1), '')

RETURN @Trimmed
END

GO

SELECT dbo.FN_RemoveNonNumeric('ABCDE# 123')

Here's a version which pulls all digits from a string; i.e. given I'm 35 years old; I was born in 1982. The average family has 2.4 children. this would return 35198224. i.e. it's good where you've got numeric data which may have been formatted as a code (e.g. #123,456,789 / 123-00005), but isn't appropriate if you're looking to pull out specific numbers (i.e. as opposed to digits / just the numeric characters) from the text. Also it only handles digits; so won't return negative signs (-) or periods .).

declare @table table (id bigint not null identity (1,1), data nvarchar(max)) 
insert @table (data) 
values ('hello 123 its 45613 then') --outputs: 12345613
,('1 some other string 98 example 4') --outputs: 1984
,('AB ABCDE # 123') --outputs: 123 
,('ABCDE# 123') --outputs: 123
,('AB: ABC# 123') --outputs: 123
; with NonNumerics as (
	select id
	, data original
	--the below line replaces all digits with blanks
	, replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(data,'0',''),'1',''),'2',''),'3',''),'4',''),'5',''),'6',''),'7',''),'8',''),'9','') nonNumeric
	from @table
)
--each iteration of the below CTE removes another non-numeric character from the original string, putting the result into the numerics column
, Numerics as (
	select id
	, replace(original, substring(nonNumeric,1,1), '') numerics
	, replace(nonNumeric, substring(nonNumeric,1,1), '') charsToreplace
	, len(replace(nonNumeric, substring(nonNumeric,1,1), '')) charsRemaining
	from NonNumerics

	union all

	select id
	, replace(numerics, substring(charsToreplace,1,1), '') numerics
	, replace(charsToreplace, substring(charsToreplace,1,1), '') charsToreplace
	, len(replace(charsToreplace, substring(charsToreplace,1,1), '')) charsRemaining
	from Numerics
	where charsRemaining > 0
)
--we select only those strings with `charsRemaining=0`; i.e. the rows for which all non-numeric characters have been removed; there should be 1 row returned for every 1 row in the original data set.
select * from Numerics where charsRemaining = 0

This code works by removing all the digits (i.e. the characters we want) from a the given strings by replacing them with blanks. Then it goes through the original string (which includes the digits) removing all of the characters that were left (i.e. the non-numeric characters), thus leaving only the digits.

The reason we do this in 2 steps, rather than just removing all non-numeric characters in the first place is there are only 10 digits, whilst there are a huge number of possible characters; so replacing that small list is relatively fast; then gives us a list of those non-numeric characters which actually exist in the string, so we can then replace that small set.

The method makes use of recursive SQL, using common table expressions (CTEs).

To add on to Ken's answer, this handles commas and spaces and parentheses

--Handles parentheses, commas, spaces, hyphens..
declare @table table (c varchar(256))
insert into @table
values
('This is a test 111-222-3344'),
('Some Sample Text (111)-222-3344'),
('Hello there 111222 3344 / How are you?'),
('Hello there 111 222 3344 ? How are you?'),
('Hello there 111 222 3344. How are you?')

select
replace(LEFT(SUBSTRING(replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',',''), PATINDEX('%[0-9.-]%', replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',','')), 8000),
           PATINDEX('%[^0-9.-]%', SUBSTRING(replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',',''), PATINDEX('%[0-9.-]%', replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',','')), 8000) + 'X') -1),'.','')
from @table

Pretty late to the party, I found the following which I though worked brilliantialy.. if anyone is still looking

SELECT
    (SELECT CAST(CAST((
        SELECT SUBSTRING(FieldToStrip, Number, 1)
        FROM master..spt_values
        WHERE Type='p' AND Number <= LEN(FieldToStrip) AND
            SUBSTRING(FieldToStrip, Number, 1) LIKE '[0-9]' FOR XML Path(''))
    AS xml) AS varchar(MAX)))
FROM
    SourceTable

Create function fn_GetNumbersOnly(@pn varchar(100))
    Returns varchar(max)
    AS
    BEGIN
      Declare @r varchar(max) ='', @len int ,@c char(1), @x int = 0
      Select @len = len(@pn)
      while @x <= @len 
      begin
        Select @c = SUBSTRING(@pn,@x,1)
    	if ISNUMERIC(@c) = 1 and @c <> '-'
    	 Select @r = @r + @c
       Select @x = @x +1
      end
    return @r
End

In your case It seems like the # will always be after teh # symbol so using CHARINDEX() with LTRIM() and RTRIM() would probably perform the best. But here is an interesting method of getting rid of ANY non digit. It utilizes a tally table and table of digits to limit which characters are accepted then XML technique to concatenate back to a single string without the non-numeric characters. The neat thing about this technique is it could be expanded to included ANY Allowed characters and strip out anything that is not allowed.

DECLARE @ExampleData AS TABLE (Col VARCHAR(100))
INSERT INTO @ExampleData (Col) VALUES ('AB ABCDE # 123'),('ABCDE# 123'),('AB: ABC# 123')

DECLARE @Digits AS TABLE (D CHAR(1))
INSERT INTO @Digits (D) VALUES ('0'),('1'),('2'),('3'),('4'),('5'),('6'),('7'),('8'),('9')

;WITH cteTally AS (
SELECT
    I = ROW_NUMBER() OVER (ORDER BY (SELECT NULL))
FROM
    @Digits d10
    CROSS APPLY @Digits d100
    --add more cross applies to cover longer fields this handles 100
)

SELECT *
FROM
    @ExampleData e
    OUTER APPLY (
    SELECT CleansedPhone = CAST((
    SELECT TOP 100
	   SUBSTRING(e.Col,t.I,1)
    FROM
	   cteTally t
	   INNER JOIN @Digits d
	   ON SUBSTRING(e.Col,t.I,1) = d.D
    WHERE
	   I <= LEN(e.Col)
    ORDER BY
	   t.I
    FOR XML PATH('')) AS VARCHAR(100))) o

 Declare @MainTable table(id int identity(1,1),TextField varchar(100))
  INSERT INTO @MainTable (TextField)
 VALUES
 ('6B32E')
 declare @i int=1
  Declare @originalWord varchar(100)=''
  WHile @i<=(Select count(*) from @MainTable)
  BEGIN
  Select @originalWord=TextField from @MainTable where id=@i

 Declare @r varchar(max) ='', @len int ,@c char(1), @x int = 0

    Select @len = len(@originalWord)
    declare @pn varchar(100)=@originalWord
    while @x <= @len 
    begin

      Select @c = SUBSTRING(@pn,@x,1)
  	if(@c!='')
  	BEGIN
			if ISNUMERIC(@c) = 0 and @c <> '-'
	BEGIN
	 Select @r = cast(@r as varchar) + cast(replace((SELECT ASCII(@c)-64),'-','') as varchar)

   end
   ELSE
   BEGIN
    Select @r = @r + @c


   END

END


    Select @x = @x +1

    END
    Select @r
  Set @i=@i+1
  END

I have created a function for this

Create FUNCTION RemoveCharacters (@text varchar(30))
RETURNS VARCHAR(30)
AS
BEGIN
declare @index as int 
declare @newtexval as varchar(30)
set @index = (select PATINDEX('%[A-Z.-/?]%', @text))
if (@index =0)
begin 
return @text
end
else
begin 
set @newtexval  = (select STUFF ( @text , @index , 1 , '' ))
return dbo.RemoveCharacters(@newtexval)
end
return 0
END
GO

Here is the answer:

DECLARE @t TABLE (tVal VARCHAR(100))
	
INSERT INTO @t VALUES('123')
INSERT INTO @t VALUES('123S')
INSERT INTO @t VALUES('A123,123')
INSERT INTO @t VALUES('a123..A123')
    
 
;WITH cte (original, tVal, n)
     AS
     (
     	 SELECT t.tVal AS original,
     	        LOWER(t.tVal)  AS tVal,
     	        65             AS n
     	 FROM   @t             AS t
     	 UNION ALL
     	 SELECT tVal AS original,
     	        CAST(REPLACE(LOWER(tVal), LOWER(CHAR(n)), '') AS VARCHAR(100)),
     	        n + 1
     	 FROM   cte
     	 WHERE  n <= 90
     )

SELECT t1.tVal  AS OldVal,
       t.tval   AS NewVal
FROM   (
           SELECT original,
                  tVal,
                  ROW_NUMBER() OVER(PARTITION BY tVal + original ORDER BY original) AS Sl
           FROM   cte
           WHERE  PATINDEX('%[a-z]%', tVal) = 0
       ) t
       INNER JOIN @t t1
            ON  t.original = t1.tVal
WHERE  t.sl = 1

You can create SQL CLR scalar function in order to be able to use regular expressions like replace patterns.

Here you can find example of how to create such function.

Having such function will solve the issue with just the following lines:

SELECT [dbo].[fn_Utils_RegexReplace] ('AB ABCDE # 123', '[^0-9]', '');
SELECT [dbo].[fn_Utils_RegexReplace] ('ABCDE# 123', '[^0-9]', '');
SELECT [dbo].[fn_Utils_RegexReplace] ('AB: ABC# 123', '[^0-9]', '');

More important, you will be able to solve more complex issues as the regular expressions will bring a whole new world of options directly in your T-SQL statements.

SELECT REGEXP_REPLACE( col, '[^[:digit:]]', '' ) AS new_col FROM my_table

DECLARE @STR VARCHAR(400)

DECLARE @specialchars VARCHAR(50) = '%[~,@,#,$,%,&,*,(,),!^?:]%'

SET @STR = '1, 45 4,3 68.00-'

WHILE PATINDEX( @specialchars, @STR ) > 0

---Remove special characters using Replace function

SET @STR = Replace(Replace(REPLACE( @STR, SUBSTRING( @STR, PATINDEX( @specialchars, @STR ), 1 ),''),'-',''), ' ','')

SELECT @STR