t-sql - Apply function to a column without sqlFunction - sql-server

Question

I've to transform a numeric code in an alphabetic code like this:
1234 -> ABCD
where 0 = 0, 1 = A, 2 = b, etc..
This is my function and how to use:
Create function dbo.DecodeNumToChar
(
#change varchar(10),
#foo varchar(10)
) returns varchar(10)
as
begin
DECLARE #II int = 1,
#result varchar(10)
;WITH x AS
(
SELECT #II as ii, STUFF(#foo,#II,1,SUBSTRING(#change,CAST(SUBSTRING(#foo,#II,1) AS INT)+1,1)) AS AA
UNION ALL
--SELECT #II+1
SELECT ii+1, STUFF(AA,ii+1,1,SUBSTRING(#change,CAST(SUBSTRING(#foo,ii+1,1) AS INT)+1,1)) AS AA
FROM x
where ii+1 <= LEN(#foo)
)
select top 1 #result = AA from x order by ii desc
return #result
end
--------------------------------------------
select brand_code, dbo.DecodeNumToChar('0ABCDEFGHI', brand_code)
from (VALUES('1234'),('5834'),('9905'),('0250')) as t(brand_code)
This function working well, but in production DB we do not have permission to create functions.
I've tryed to transform this function into CTE like this
declare #change varchar(9) = 'ABCDEFGHI'
DECLARE #II int = 0
;WITH x AS
(
SELECT TOP (10) n = ROW_NUMBER() OVER (ORDER BY Number)
FROM master.dbo.spt_values ORDER BY Number
),
innerCTE as
(
SELECT x.n, SUBSTRING(t.brand_code, x.n, 1) chnum,
case SUBSTRING(t.brand_code, x.n, 1)
when '0' then '0'
else char(65-1+SUBSTRING(t.brand_code, x.n, 1))
end chalfa, t.brand_code
FROM x INNER JOIN (VALUES('1234'),('5834'),('9905'),('0250')) as t(brand_code)
ON x.n <= LEN(t.brand_code)
),
CTE as
(
select n, chnum, chalfa, brand_code, stuff(brand_code, n, 1, chalfa) as code
from innerCTE
union all
select n+1, chnum, chalfa, brand_code, STUFF(code, n+1, 1, chalfa) as code
from cte
where n+1 <= LEN(cte.brand_code)
)
--select * from innerCTE
select * from CTE;
or using CROSS APPLY like this example: Example_1
or using CROSS APPLY with PIVOT like this example: Example_2
but my experience on SQL is low and I have not been able to get the correct result.
I'd like to have this:
brand_code decoded_code
1234 ABCD
5834 EHCD
9905 II0E
0250 0BE0
thanks

Answer 1

If using SQL 2017+
DECLARE #integerValues TABLE ([I] INT);
INSERT INTO #integerValues ([I])
VALUES
(1234),
(6485834),
(99084705),
(1124601);
SELECT
T.[I],
STRING_AGG(
CASE SUBSTRING(T.[S], V.[number] + 1, 1)
WHEN '9' THEN 'I'
WHEN '8' THEN 'H'
WHEN '7' THEN 'G'
WHEN '6' THEN 'F'
WHEN '5' THEN 'E'
WHEN '4' THEN 'D'
WHEN '3' THEN 'C'
WHEN '2' THEN 'B'
WHEN '1' THEN 'A'
ELSE '0'
END,
'') WITHIN GROUP (ORDER BY T.[I]) [S]
FROM
(SELECT [I], CAST([I] AS VARCHAR(10)) [S] FROM #integerValues) T
JOIN
[master]..[spt_values] V ON V.[number] < LEN(T.[S])
WHERE
V.[type] = 'P';
or, if 2016 or earlier
DECLARE #integerValues TABLE ([I] INT);
INSERT INTO #integerValues ([I])
VALUES
(1234),
(6485834),
(99084705),
(1124601);
SELECT
[I],
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
CAST([I] AS VARCHAR(10)),
'1',
'A'),
'2',
'B'),
'3',
'C'),
'4',
'D'),
'5',
'E'),
'6',
'F'),
'7',
'G'),
'8',
'H'),
'9',
'I') [S]
FROM
#integerValues;

Answer 2

The following solution uses a FOR XML subquery and some mod (%) operations against the integer value to split each digit, then a mapping table to relate each digit with a character. The FOR XML returns the digits back in order.
DECLARE #IntegerValues TABLE (Integer INT)
INSERT INTO #IntegerValues (Integer)
VALUES
(1234),
(6485834),
(99084705),
(1124601)
SELECT
T.Integer,
Conversion = (
SELECT
'' + M.Character -- Must have no declared alias (for xml)
FROM
(VALUES
(1, T.Integer % 10),
(2, T.Integer / 10 % 10),
(3, T.Integer / 100 % 10),
(4, T.Integer / 1000 % 10),
(5, T.Integer / 10000 % 10),
(6, T.Integer / 100000 % 10),
(7, T.Integer / 1000000 % 10),
(8, T.Integer / 10000000 % 10),
(9, T.Integer / 100000000 % 10),
(10, T.Integer / 1000000000 % 10),
(11, T.Integer / 10000000000 % 10)
) AS X(OrdinalPosition, SplitDigit)
INNER JOIN (VALUES
(0, '0'),
(1, 'A'),
(2, 'B'),
(3, 'C'),
(4, 'D'),
(5, 'E'),
(6, 'F'),
(7, 'G'),
(8, 'H'),
(9, 'I')
) AS M(Digit, Character) ON X.SplitDigit = M.Digit
WHERE
X.OrdinalPosition <= FLOOR(LOG10(T.Integer)) + 1 -- This expression returns the number of digits
ORDER BY
X.OrdinalPosition DESC
FOR XML
PATH('')
)
FROM
#IntegerValues AS T
Result:
Integer Conversion
1234 ABCD
6485834 FDHEHCD
99084705 II0HDG0E
1124601 AABDF0A
There is probably a cleaner way to write the mappings and the mod operations, but this should give an idea.

Answer 3

I've find a solution using recursive CTE.
declare #change varchar(10) = '0ABCDEFGHI'
DECLARE #II int = 1;
with BRANDS as
(
select * from (VALUES('1234'),('5834'),('9905'),('0250')) as t(brand_code)
),
CTE as
(
select #II as ii, BRAND_CODE,
STUFF(brand_code,#II,1,SUBSTRING(#change,CAST(SUBSTRING(brand_code,#II,1) AS INT)+1,1)) AS AA
from BRANDS
union all
select c.ii+1, b.BRAND_CODE,
STUFF(AA,c.ii+1,1,SUBSTRING(#change,CAST(SUBSTRING(AA,c.ii+1,1) AS INT)+1,1)) AS AA
from BRANDS b
inner join CTE c on b.BRAND_CODE = c.BRAND_CODE
where c.ii < LEN(b.BRAND_CODE)
)
select BRAND_CODE, AA as NewCode from CTE where ii = len(brand_code) order by BRAND_CODE, ii

Answer 4

This is the code for the suggestion from #Martin Smith to use 10 nested replace.
DECLARE #change char(10) = '0ABCDEFGHI';
--------------------------------------------
select brand_code,
REPLACE( REPLACE( REPLACE( REPLACE( REPLACE(
REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( brand_code
, '0', SUBSTRING( #change, 1, 1)) , '1', SUBSTRING( #change, 2, 1))
, '2', SUBSTRING( #change, 3, 1)) , '3', SUBSTRING( #change, 4, 1))
, '4', SUBSTRING( #change, 5, 1)) , '5', SUBSTRING( #change, 6, 1))
, '6', SUBSTRING( #change, 7, 1)) , '7', SUBSTRING( #change, 8, 1))
, '8', SUBSTRING( #change, 9, 1)) , '9', SUBSTRING( #change, 10, 1))
from (VALUES('1234'),('5834'),('9905'),('0250')) as t(brand_code);