SQL Server Remove some specific characters from string - sql

Question

SQL Server: I would like to create a function that removes specific characters from a string, based on parameters.
parameter1 is original string
parameter2 is characters want to removed from original string
For example :
call MyRemoveFunc('32.87.65.54.89', '87.65' ) -- this will return '32.54.89'
call MyRemoveFunc('11.23.45', '23' ) -- this will return '11.45'
call MyRemoveFunc('14.99.16.84', '84.14' ) -- this will return '99.16'
call MyRemoveFunc('11.23.45.65.31.90', '23' ) -- this will return 11.45.65.31.90
call MyRemoveFunc('34.35.36', '35' ) -- this will return 34.36
call MyRemoveFunc('34.35.36.76.44.22', '35' ) -- this will return 34.36.76.44.22
call MyRemoveFunc('34', '34' ) -- this will return blank
call MyRemoveFunc('45.23.11', '45.11' ) -- this will return 23
Thanks

Answer 1

Here is one way using Recursive CTE and Split string function
;WITH data
AS (SELECT org_string,
replace_with,
cs.Item,
cs.ItemNumber
FROM (VALUES ('32.87.65.54.89','87.65' ),
('11.23.45','23' ),
('14.99.16.84','84.14' ),
('11.23.45.65.31.90','23' ),
('34.35.36','35' ),
('34.35.36.76.44.22','35' ),
('34','34' ),
('45.23.11','45.11')) tc (org_string, replace_with)
CROSS apply [Delimitedsplit8k](replace_with, '.') cs),
cte
AS (SELECT org_string,
replace_with,
Item,
Replace('.' + org_string, + '.' + Item, '') AS result,
ItemNumber
FROM data
WHERE ItemNumber = 1
UNION ALL
SELECT d.org_string,
d.replace_with,
d.Item,
CASE
WHEN LEFT(Replace('.' + result, '.' + d.Item, ''), 1) = '.' THEN Stuff(Replace('.' + result, '.' + d.Item, ''), 1, 1, '')
ELSE Replace('.' + result, '.' + d.Item, '')
END,
d.ItemNumber
FROM cte c
JOIN data d
ON c.org_string = d.org_string
AND d.ItemNumber = c.ItemNumber + 1)
SELECT TOP 1 WITH ties org_string,
replace_with,
result = Isnull(Stuff(result, 1, 1, ''), '')
FROM cte
ORDER BY Row_number()OVER(partition BY org_string ORDER BY ItemNumber DESC)
Result :
╔═══════════════════╦══════════════╦════════════════╗
║ org_string ║ replace_with ║ result ║
╠═══════════════════╬══════════════╬════════════════╣
║ 11.23.45 ║ 23 ║ 11.45 ║
║ 11.23.45.65.31.90 ║ 23 ║ 11.45.65.31.90 ║
║ 14.99.16.84 ║ 84.14 ║ 99.16 ║
║ 34 ║ 34 ║ ║
║ 34.35.36 ║ 35 ║ 34.36 ║
║ 34.35.36.76.44.22 ║ 35 ║ 34.36.76.44.22 ║
║ 45.23.11 ║ 45.11 ║ 23 ║
║ 32.87.65.54.89 ║ 87.65 ║ 32.54.89 ║
╚═══════════════════╩══════════════╩════════════════╝
The above code can be converted to a user defined function. I will suggest to create Inline Table valued function instead of Scalar function if you have more records.
Split string Function code referred from http://www.sqlservercentral.com/articles/Tally+Table/72993/
CREATE FUNCTION [dbo].[DelimitedSplit8K]
(#pString VARCHAR(8000), #pDelimiter CHAR(1))
RETURNS TABLE WITH SCHEMABINDING AS
RETURN
--===== "Inline" CTE Driven "Tally Table" produces values from 0 up to 10,000...
-- enough to cover NVARCHAR(4000)
WITH E1(N) AS (
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
), --10E+1 or 10 rows
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 (--==== This provides the "base" CTE and limits the number of rows right up front
-- for both a performance gain and prevention of accidental "overruns"
SELECT TOP (ISNULL(DATALENGTH(#pString),0)) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
),
cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter)
SELECT 1 UNION ALL
SELECT t.N+1 FROM cteTally t WHERE SUBSTRING(#pString,t.N,1) = #pDelimiter
),
cteLen(N1,L1) AS(--==== Return start and length (for use in substring)
SELECT s.N1,
ISNULL(NULLIF(CHARINDEX(#pDelimiter,#pString,s.N1),0)-s.N1,8000)
FROM cteStart s
)
--===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found.
SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY l.N1),
Item = SUBSTRING(#pString, l.N1, l.L1)
FROM cteLen l
;
GO

Answer 2

You could try this..
CREATE FUNCTION StringSpecialReplace(#TargetString VARCHAR(1000),
#InputString VARCHAR(1000))
returns VARCHAR(1000)
AS
BEGIN
declare #result as varchar(1000)
;with CTE1 AS
(
SELECT LTRIM(RTRIM(m.n.value('.[1]','varchar(8000)'))) AS Certs
FROM (SELECT CAST('<XMLRoot><RowData>' + REPLACE(#TargetString,'.','</RowData><RowData>') + '</RowData></XMLRoot>' AS XML) AS x)t
CROSS APPLY x.nodes('/XMLRoot/RowData')m(n)
),
CTE2 AS
(
SELECT LTRIM(RTRIM(m.n.value('.[1]','varchar(8000)'))) AS Certs
FROM (SELECT CAST('<XMLRoot><RowData>' + REPLACE(#InputString,'.','</RowData><RowData>') + '</RowData></XMLRoot>' AS XML) AS x)t
CROSS APPLY x.nodes('/XMLRoot/RowData')m(n)
)
SELECT
#Result = CASE
WHEN #Result IS NULL
THEN certs
ELSE #Result + '.' + certs
END
FROM CTE1 where certs not in (select certs from CTE2)
return #Result
END

Answer 3

CREATE FUNCTION MyRemoveFunc (
#OrigString VARCHAR(8000),
#RemovedString VARCHAR(max)
)
RETURNS varchar(max)
BEGIN
DECLARE #xml XML
SET #xml='<n>'+REPLACE(#RemovedString,'.','</n><n>')+'</n>'
SET #OrigString='.'+#OrigString+'.'
SELECT #OrigString=REPLACE(#OrigString,'.'+s.b.value('.','varchar(200)')+'.','.')
FROM #xml.nodes('n')s(b)
RETURN CASE WHEN LEN(#OrigString)>2 THEN SUBSTRING(#OrigString,2,LEN(#OrigString)-2) ELSE '' END
END
SELECT t.*,dbo.MyRemoveFunc(t.o,t.r)
FROM (VALUES ('32.87.65.54.89','87.65' ),
('11.23.45','23' ),
('14.99.16.84','84.14' ),
('11.23.45.65.31.90','23' ),
('34.35.36','35' ),
('34.35.36.76.44.22','35' ),
('34','34' ),
('45.23.11','45.11')) t (o, r)
o r
----------------- ----- -------------------------
32.87.65.54.89 87.65 32.54.89
11.23.45 23 11.45
14.99.16.84 84.14 99.16
11.23.45.65.31.90 23 11.45.65.31.90
34.35.36 35 34.36
34.35.36.76.44.22 35 34.36.76.44.22
34 34
45.23.11 45.11 23