Reverse order of elements in a string - sql

Question

I have the following string:
1119/2/483/11021
I would like to reverse the order of the elements in that string. Desired output:
11021/483/2/1119
T-SQL Version 2014

Answer 1

You need an ordered split function, e.g. (inspiration):
CREATE FUNCTION dbo.SplitOrdered
(
#list nvarchar(max),
#delim nvarchar(10)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
RETURN
(
WITH w(n) AS (SELECT 0 FROM (VALUES (0),(0),(0),(0)) w(n)),
k(n) AS (SELECT 0 FROM w a, w b),
r(n) AS (SELECT 0 FROM k a, k b, k c, k d, k e, k f, k g, k h),
p(n) AS (SELECT TOP (COALESCE(LEN(#list), 0))
ROW_NUMBER() OVER (ORDER BY ##SPID) -1 FROM r),
spots(p) AS
(
SELECT n FROM p
WHERE (SUBSTRING(#list, n, LEN(#delim + 'x') - 1) LIKE #delim OR n = 0)
),
parts(p,val) AS
(
SELECT p, SUBSTRING(#list, p + LEN(#delim + 'x') - 1,
LEAD(p, 1, 2147483647) OVER (ORDER BY p) - p - LEN(#delim))
FROM spots AS s
)
SELECT listpos = ROW_NUMBER() OVER (ORDER BY p),
Item = LTRIM(RTRIM(val))
FROM parts
);
Then you can reassemble using STRING_AGG() (if SQL Server 2017 or better) or FOR XML PATH on lower versions:
SQL Server 2017 +
DECLARE #OriginalString nvarchar(255) = N'1119/2/483/11021';
SELECT NewString = STRING_AGG(o.Item, N'/')
WITHIN GROUP (ORDER BY listpos DESC)
FROM dbo.SplitOrdered(#OriginalString, N'/') AS o;
SQL Server < 2017
DECLARE #OriginalString nvarchar(255) = N'1119/2/483/11021';
SELECT NewString = STUFF(
(SELECT N'/' + o.Item
FROM dbo.SplitOrdered(#OriginalString, N'/') AS o
ORDER BY o.listpos DESC
FOR XML PATH(''), TYPE).value(N'./text()[1]', N'nvarchar(max)'),1,1,N'');
Example db<>fiddle

Answer 2

Please try the following solution based on the built-in PARSENAME() T-SQL function.
SQL
-- DDL and sample data population, start
DECLARE #tbl TABLE (ID INT IDENTITY PRIMARY KEY, Tokens VARCHAR(MAX));
INSERT INTO #tbl (Tokens) VALUES
('1119/2/483/11021'),
('1120/25/484/1102');
-- DDL and sample data population, end
SELECT tbl.*
, PARSENAME(c, 1) + '/' +
PARSENAME(c, 2) + '/' +
PARSENAME(c, 3) + '/' +
PARSENAME(c, 4) AS Result
FROM #tbl AS tbl
CROSS APPLY (VALUES (REPLACE(Tokens, '/', '.') )) AS t(c);
Output
+----+------------------+------------------+
| ID | Tokens | Result |
+----+------------------+------------------+
| 1 | 1119/2/483/11021 | 11021/483/2/1119 |
| 2 | 1120/25/484/1102 | 1102/484/25/1120 |
+----+------------------+------------------+

Answer 3

First, split the string and convert it into a column then order by desc and display into multiple row values into a single row. In the following code, you can set any string and split char.
Try following way.
DECLARE #S varchar(max) ,
#Split char(1),
#X xml
DECLARE #Names VARCHAR(8000)
SELECT #S = '1119/2/483/11021',
#Split = '/'
SELECT #X = CONVERT(xml,' <root> <myvalue>' +
REPLACE(#S,#Split,'</myvalue> <myvalue>') + '</myvalue> </root> ')
select #Names = COALESCE(#Names + '/', '') + Value from (
select rowno,Value from (
select ROW_NUMBER() OVER(ORDER BY d) AS rowno , Value from (
SELECT T.c.value('.','varchar(20)') as Value,0 as d
FROM #X.nodes('/root/myvalue') T(c)
) m
) r
) t order by t.rowno desc
select #Names as ReverseString

Answer 4

Splitting the string into sub-strings, and then joining them back up, is most likely going to be a good approach.
Some comments mention using string-reverse, but that doesnt seem to be a good approach at all in your case, since you just want to reverse the order of words within the current string, not actually reverse the entire text-string character-by-character.
PS: string_split does not guarantee the order of the chunks!