Split words with a capital letter in sql - sql

Question

Does anyone know how to split words starting with capital letters from a string?
Example:
DECLARE #var1 varchar(100) = 'OneTwoThreeFour'
DECLARE #var2 varchar(100) = 'OneTwoThreeFourFive'
DECLARE #var3 varchar(100) = 'One'
SELECT #var1 as Col1, <?> as Col2
SELECT #var2 as Col1, <?> as Col2
SELECT #var3 as Col1, <?> as Col2
expected result:
Col1 Col2
OneTwoThreeFour One Two three Four
OneTwoThreeFourFive One Two Three Four Five
One One
If this is not possible (or if too long) an scalar function would be okay as well.

Answer 1

Here is a function I created that is similar to the "removing non-alphabetic characters". How to strip all non-alphabetic characters from string in SQL Server?
This one uses a case sensitive collation which actively seeks out a non-space/capital letter combination and then uses the STUFF function to insert the space. This IS a scalar UDF, so some folks will immediately say that it will be slower than other solutions. To that notion, I say, please test it. This function does not use any table data and only loops as many times as necessary, so it will likely give you very good performance.
Create Function dbo.Split_On_Upper_Case(#Temp VarChar(1000))
Returns VarChar(1000)
AS
Begin
Declare #KeepValues as varchar(50)
Set #KeepValues = '%[^ ][A-Z]%'
While PatIndex(#KeepValues collate Latin1_General_Bin, #Temp) > 0
Set #Temp = Stuff(#Temp, PatIndex(#KeepValues collate Latin1_General_Bin, #Temp) + 1, 0, ' ')
Return #Temp
End
Call it like this:
Select dbo.Split_On_Upper_Case('OneTwoThreeFour')
Select dbo.Split_On_Upper_Case('OneTwoThreeFour')
Select dbo.Split_On_Upper_Case('One')
Select dbo.Split_On_Upper_Case('OneTwoThree')
Select dbo.Split_On_Upper_Case('stackOverFlow')
Select dbo.Split_On_Upper_Case('StackOverFlow')

Answer 2

Here is a function I have just created.
FUNCTION
CREATE FUNCTION dbo.Split_On_Upper_Case
(
#String VARCHAR(4000)
)
RETURNS VARCHAR(4000)
AS
BEGIN
DECLARE #Char CHAR(1);
DECLARE #i INT = 0;
DECLARE #OutString VARCHAR(4000) = '';
WHILE (#i <= LEN(#String))
BEGIN
SELECT #Char = SUBSTRING(#String, #i,1)
IF (#Char = UPPER(#Char) Collate Latin1_General_CS_AI)
SET #OutString = #OutString + ' ' + #Char;
ELSE
SET #OutString = #OutString + #Char;
SET #i += 1;
END
SET #OutString = LTRIM(#OutString);
RETURN #OutString;
END
Test Data
DECLARE #TABLE TABLE (Strings VARCHAR(1000))
INSERT INTO #TABLE
VALUES ('OneTwoThree') ,
('FourFiveSix') ,
('SevenEightNine')
Query
SELECT dbo.Split_On_Upper_Case(Strings) AS Vals
FROM #TABLE
Result Set
╔══════════════════╗
║ Vals ║
╠══════════════════╣
║ One Two Three ║
║ Four Five Six ║
║ Seven Eight Nine ║
╚══════════════════╝

Answer 3

If a single query is needed 26 REPLACE can be used to check every upper case letter like
SELECT #var1 col1, REPLACE(
REPLACE(
REPLACE(
...
REPLACE(#var1, 'A', ' A')
, ...
, 'X', ' X')
, 'Y', ' Y')
, 'Z', ' Z') col2
Not the most beautiful thing but it'll work.
EDIT
Just to add another function to do the same thing in a different way of the other answers
CREATE FUNCTION splitCapital (#param Varchar(MAX))
RETURNS Varchar(MAX)
BEGIN
Declare #ret Varchar(MAX) = '';
declare #len int = len(#param);
WITH Base10(N) AS (
SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7
UNION ALL SELECT 8 UNION ALL SELECT 9
), Chars(N) As (
Select TOP(#len)
nthChar
= substring(#param, u.N + t.N*10 + h.N*100 + th.N*1000 + 1, 1)
Collate Latin1_General_CS_AI
FROM Base10 u
CROSS JOIN Base10 t
CROSS JOIN Base10 h
CROSS JOIN Base10 th
WHERE u.N + t.N*10 + h.N*100 + th.N*1000 < #len
ORDER BY u.N + t.N*10 + h.N*100 + th.N*1000
)
SELECT #ret += Case nthChar
When UPPER(nthChar) Then ' '
Else ''
End + nthChar
FROM Chars
RETURN #ret;
END
This one uses the possibility of TSQL to concatenate string variable, I had to use the TOP N trick to force the Chars CTE rows in the right order

Answer 4

Build a Numbers table. There are some excellent posts on SO to show you how to do this. Populate it with values up the maximum length of your input string. Select the values from 1 through the actual length of the current input string. Cross join this list of numbers to the input string. Use the result to SUBSTRING() each character. Then you can either compare the resulting list of one-charachter values to a pre-populated table-valued variable or convert each character to an integer using ASCII() and choose only those between 65 ('A') and 90 ('Z'). At this point you have a list which is the position of each upper-case character in your input string. UNION the maximum length of your input string onto the end of this list. You'll see why in just a second. Now you can SUBSTRING() your input variable, starting at the Number given by row N and taking a length of (the Number given by row N+1) - (The number given by row N). This is why you have to UNION the extra Number on the end. Finally concatenate all these substring together, space-separated, using the algorithm of your choice.
Sorry, don't have an instance in front of me to try out code. Sounds like a fun task. I think doing it with nested SELECT statements will get convoluted and un-maintainable; better to lay it out as CTEs, IMHO.

Answer 5

I know that there are already some good answers out there, but if you wanted to avoid creating a function, you could also use a recursive CTE to accomplish this. It's certainly not a clean way of doing this, but it works.
DECLARE
#camelcase nvarchar(4000) = 'ThisIsCamelCased'
;
WITH
split
AS
(
SELECT
[iteration] = 0
,[string] = #camelcase
UNION ALL
SELECT
[iteration] = split.[iteration] + 1
,[string] = STUFF(split.[string], pattern.[index] + 1, 0, ' ')
FROM
split
CROSS APPLY
( SELECT [index] = PATINDEX(N'%[^ ][A-Z]%' COLLATE Latin1_General_Bin, split.[string]) )
pattern
WHERE
pattern.[index] > 0
)
SELECT TOP (1)
[spaced] = split.[string]
FROM
split
ORDER BY
split.[iteration] DESC
;
As I said, this isn't a pretty way to write a query, but I use things like this when I'm just writing up some ad-hoc queries where I would not want to add new artifacts to the database. You could also use this to create your function as an inline table valued function, which is always a tad nicer.

Answer 6

Please Try This:
declare #t nvarchar (100) ='IamTheTestString'
declare #len int
declare #Counter int =0
declare #Final nvarchar (100) =''
set #len =len( #t)
while (#Counter <= #len)
begin
set #Final= #Final + Case when ascii(substring (#t,#Counter,1))>=65 and
ascii(substring (#t,#Counter,1))<=90 then ' '+substring (#t,#Counter,1) else
substring (#t,#Counter,1) end
set #Counter=#Counter+1
end
print ltrim(#Final)