Split string in SQL Server to a maximum length, returning each as a row - sql

Question

Is there a way to split a string (from a specific column) to n-number chars without breaking words, with each result in its own row?
Example:
2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the PSO department Customer states terms should be Net 60 not Net 30. Please review signed contract for this information.
Results:
2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the
PSO department Customer states terms should be Net 60 not Net 30.
Please review signed contract for this information.
I know I can use charindex to find the last space, but im not sure how i can get the remaining ones and return them as rows.

Answer 1

Try something like this. May be your can create a SQL function of following implementation.
DECLARE #Str VARCHAR(1000)
SET #Str = '2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the PSO department Customer states terms should be Net 60 not Net 30. Please review signed contract for this information.'
DECLARE #End INT
DECLARE #Split INT
SET #Split = 100
declare #SomeTable table
(
Content varchar(3000)
)
WHILE (LEN(#Str) > 0)
BEGIN
IF (LEN(#Str) > #Split)
BEGIN
SET #End = LEN(LEFT(#Str, #Split)) - CHARINDEX(' ', REVERSE(LEFT(#Str, #Split)))
INSERT INTO #SomeTable VALUES (RTRIM(LTRIM(LEFT(LEFT(#Str, #Split), #End))))
SET #Str = SUBSTRING(#Str, #End + 1, LEN(#Str))
END
ELSE
BEGIN
INSERT INTO #SomeTable VALUES (RTRIM(LTRIM(#Str)))
SET #Str = ''
END
END
SELECT *
FROM #SomeTable
Output will be like this:
2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the
PSO department Customer states terms should be Net 60 not Net 30. Please review signed contract
for this information.

Answer 2

I read some articles and each of them has error or bad performance or not working in small or big length of chunk we want. You can read my comments even in this article below of any answer. Finally i found a good answer and decided to share it in this question. I didn't check performance in various scenarios but i think is acceptable and working fine for small and big chunk length.
This is the code:
CREATE function SplitString
(
#str varchar(max),
#length int
)
RETURNS #Results TABLE( Result varchar(50),Sequence INT )
AS
BEGIN
DECLARE #Sequence INT
SET #Sequence = 1
DECLARE #s varchar(50)
WHILE len(#str) > 0
BEGIN
SET #s = left(#str, #length)
INSERT #Results VALUES (#s,#Sequence)
IF(len(#str)<#length)
BREAK
SET #str = right(#str, len(#str) - #length)
SET #Sequence = #Sequence + 1
END
RETURN
END
and source is #Rhyno answer on this question: TSQL UDF To Split String Every 8 Characters
Hope this help.

Answer 3

Just to see if it could be done, I came up with a solution that doesn't loop. It's based on somebody else's function to split a string based on a delimiter.
Note:
This requires that you know the maximum token length ahead of time. The function will stop returning lines upon encountering a token longer than the specified line length. There are probably other bugs lurking as well, so use this code at your own caution.
CREATE FUNCTION SplitLines
(
#pString VARCHAR(7999),
#pLineLen INT,
#pDelim CHAR(1)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
RETURN
WITH
E1(N) AS ( --=== Create Ten 1's
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 --10
),
E2(N) AS (SELECT 1 FROM E1 a, E1 b), --100
E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10,000
cteTally(N) AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT N)) FROM E4),
lines AS (
SELECT TOP 1
1 as LineNumber,
ltrim(rtrim(SUBSTRING(#pString, 1, N))) as Line,
N + 1 as start
FROM cteTally
WHERE N <= DATALENGTH(#pString) + 1
AND N <= #pLineLen + 1
AND SUBSTRING(#pString + #pDelim, N, 1) = #pDelim
ORDER BY N DESC
UNION ALL
SELECT LineNumber, Line, start
FROM (
SELECT LineNumber + 1 as LineNumber,
ltrim(rtrim(SUBSTRING(#pString, start, N))) as Line,
start + N + 1 as start,
ROW_NUMBER() OVER (ORDER BY N DESC) as r
FROM cteTally, lines
WHERE N <= DATALENGTH(#pString) + 1 - start
AND N <= #pLineLen
AND SUBSTRING(#pString + #pDelim, start + N, 1) = #pDelim
) A
WHERE r = 1
)
SELECT LineNumber, Line
FROM lines
It's actually quite fast and you can do cool things like join on it. Here's a simple example that gets the first 'line' from every row in a table:
declare #table table (
id int,
paragraph varchar(7999)
)
insert into #table values (1, '2012-04-24 Change request #3 for the contract per terms and conditions and per John Smith in the PSO department Customer states terms should be Net 60 not Net 30. Please review signed contract for this information.')
insert into #table values (2, 'Is there a way to split a string (from a specific column) to n-number chars without breaking words, with each result in its own row?')
select t.id, l.LineNumber, l.Line, len(Line)
from #table t
cross apply SplitLines(t.paragraph, 42, ' ') l
where l.LineNumber = 1

Answer 4

I know this is a bit late but a recursive cte would allow to achieve this.
Also you could make use of a seed table containing a sequence of numbers to feed into the substring as a multiplier for the start index.