Split delimited string in SQL Server - sql

Question

I have the following slash-delimited example strings and need to split them:
Record---String
1--------ABC
2--------DEF/123
3--------GHI/456/XYZ
The strings will always have 1 - 3 parts; no more, no less.
To split them I have been using this function:
CREATE FUNCTION [dbo].[Split] (
#chunk VARCHAR(4000)
,#delimiter CHAR(1)
,#index INT
)
RETURNS VARCHAR(1000)
AS
BEGIN
DECLARE #curIndex INT = 0
,#pos INT = 1
,#prevPos INT = 0
,#result VARCHAR(1000)
WHILE #pos > 0
BEGIN
SET #pos = CHARINDEX(#delimiter, #chunk, #prevPos);
IF (#pos > 0)
BEGIN -- Characters between position and previous position
SET #result = SUBSTRING(#chunk, #prevPos, #pos - #prevPos)
END
ELSE
BEGIN -- Last Delim
SET #result = SUBSTRING(#chunk, #prevPos, LEN(#chunk))
END
IF (#index = #curIndex)
BEGIN
RETURN #result
END
SET #prevPos = #pos + 1
SET #curIndex = #curIndex + 1;
END
RETURN '' -- Else Empty
END
To split the strings, I call this function like so:
MyField1 = dbo.Split(MyInputString, '/', 0),
MyField2 = dbo.Split(MyInputString, '/', 1),
MyField3 = dbo.Split(MyInputString, '/', 2)
The expected results would be
Record 1:
MyField1 = ABC
MyField2 = NULL
MyField3 = NULL
Record 2:
MyField1 = DEF
MyField2 = 123
MyField3 = NULL
Record 3:
MyField1 = GHI
MyField2 = 456
MyField3 = XYZ
It is almost doing what I had hoped, except the last character of MyField1 for Record 1 is being truncated resulting in "AB" instead of "ABC". I believe this is because there is no slash delimiter for this one-part string.
Unfortunately, I did not write this function and my SQL skills are a bit weak. What should I change to make this function return proper results when there is no delimiter in the string?

Answer 1

The following fixes your "SPLIT" function. Add the following line just before the WHILE.
SET #chunk = #chunk + '/'

Answer 2

I would move the charindex to before the while:
alter FUNCTION [dbo].[Split] (
#chunk VARCHAR(4000)
,#delimiter CHAR(1)
,#index INT
)
RETURNS VARCHAR(1000)
AS
BEGIN
DECLARE #curIndex INT = 0
,#pos INT = 1
,#prevPos INT = 0
,#result VARCHAR(1000)
SET #pos = CHARINDEX(#delimiter, #chunk, #prevPos);
if #pos= 0 return #chunk
WHILE #pos > 0
BEGIN
SET #pos = CHARINDEX(#delimiter, #chunk, #prevPos);
IF (#pos > 0)
BEGIN -- Characters between position and previous position
SET #result = SUBSTRING(#chunk, #prevPos, #pos - #prevPos)
END
ELSE
BEGIN -- Last Delim
SET #result = SUBSTRING(#chunk, #prevPos, LEN(#chunk))
END
IF (#index = #curIndex)
BEGIN
RETURN #result
END
SET #prevPos = #pos + 1
SET #curIndex = #curIndex + 1;
SET #pos = CHARINDEX(#delimiter, #chunk, #prevPos);
END
RETURN #chunk -- Else Empty
END

Answer 3

DECLARE #curIndex INT = 0
,#pos INT = 1
,#prevPos INT = 0
,#result VARCHAR(1000)
if CHARINDEX(#delimiter, #chunk, #prevPos)= 0
set #chunk=#chunk+#delimiter
using (#johns correct solution)