T-SQL: split string on multiple delimiters - tsql

Question

I have been given a T-SQL task: to convert/format names which are in ALL CAPS into Title Case. I have decided that splitting the names into tokens, and capitalizing the first letter out of each token, would be a reasonable approach (I am willing to take advice if there's a better option, especially in T-SQL).
That said, to accomplish this, I'd have to split the name fields on spaces AND dashes, hyphens, etc. Then, once it is tokenized, I can worry about normalizing the case.
Is there any reasonable way to split a string along any delimiter in a list?

Answer 1

If ease & performance is important then grab a copy of PatExtract8k.
Here's a basic example where I split on any character that is not a letter or number ([^a-z0-9]):
-- Sample String
DECLARE #string VARCHAR(8000) = 'abc.123&xyz!4445556__5566^rrr';
-- Basic Use
SELECT pe.* FROM samd.patExtract8K(#string,'[^a-z0-9]') AS pe;
Output:
itemNumber itemIndex itemLength item
--------------- ----------- ----------- -------------
1 1 3 abc
2 5 3 123
3 9 3 xyz
4 13 7 4445556
5 22 4 5566
6 27 3 rrr
It returns what you need as well as:
the length of the item (ItemLength)
It's position in the string (ItemIndex)
It's ordinal position in the string (ItemNumber.)
Now against a table. Here we're doing the same thing but I'll explicitly call out the characters I want to use as a delimiter. Here it's any of these characters: *.&,?%/>
-- Sample Table
DECLARE #table TABLE (SomeId INT IDENTITY, SomeString VARCHAR(100));
INSERT #table VALUES('abc***332211,,XXX'),('abc.123&&555%jjj'),('ll/111>ff?12345');
SELECT t.*, pe.*
FROM #table AS t
CROSS APPLY samd.patExtract8K(t.SomeString,'[*.&,?%/>]') AS pe;
This returns:
SomeId SomeString itemNumber itemIndex itemLength item
----------- ------------------- ------------ ---------- ----------- ---------
1 abc***332211,,XXX 1 1 3 abc
1 abc***332211,,XXX 2 7 6 332211
1 abc***332211,,XXX 3 15 3 XXX
2 abc.123&&555%jjj 1 1 3 abc
2 abc.123&&555%jjj 2 5 3 123
2 abc.123&&555%jjj 3 10 3 555
2 abc.123&&555%jjj 4 14 3 jjj
3 ll/111>ff?12345 1 1 2 ll
3 ll/111>ff?12345 2 4 3 111
3 ll/111>ff?12345 3 8 2 ff
3 ll/111>ff?12345 4 11 5 12345
On the other hand - If I wanted to extract the delimiters I could change the pattern like this: [^*.&,?%/>]. Now the same query returns:
SomeId itemNumber itemIndex itemLength item
----------- -------------------- -------------------- ----------- ---------
1 1 4 3 ***
1 2 13 2 ,,
2 1 4 1 .
2 2 8 2 &&
2 3 13 1 %
3 1 3 1 /
3 2 7 1 >
3 3 10 1 ?