SQL Function to parse a delimited string

CREATE FUNCTION ParseDelimitedString
(
@str AS VARCHAR (8000),
@delimiter AS VARCHAR (5)
)
RETURNS @RETTABLE TABLE(string VARCHAR(50))

AS

BEGIN
WHILE LEN(@STR) > 0
BEGIN
IF CHARINDEX(@DELIMITER, @STR) = 0
BEGIN
INSERT INTO @RETTABLE VALUES (LTRIM(RTRIM(@STR)))
SET @STR = ''
END
ELSE
BEGIN
INSERT INTO @RETTABLE
VALUES (SUBSTRING(@STR, 1, CHARINDEX(@DELIMITER, @STR)-1))
SET @STR = RIGHT(@STR, LEN(@STR) - CHARINDEX(@DELIMITER, @STR) - 1)
END
END

RETURN
END
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Usage:
select * from dbo.ParseDelimitedString('cat, dog, frog, pig', ', ')