User Defined Functions (UDF) to Reverse String – UDF_ReverseString

UDF_ReverseString
UDF_ReverseString User Defined Functions returns the Reversed String starting from certain position.
First parameters takes the string to be reversed.
Second parameters takes the position from where the string starts reversing.

Script of UDF_ReverseString function to return Reverse String.

CREATE FUNCTION UDF_ReverseString
( @StringToReverse VARCHAR(8000),
@StartPosition INT )
RETURNS VARCHAR(8000)
AS
BEGIN
IF (@StartPosition <= 0)
OR (@StartPosition > LEN(@StringToReverse))
RETURN (REVERSE(@StringToReverse))
RETURN (STUFF (@StringToReverse,
@StartPosition,
LEN(@StringToReverse) - @StartPosition + 1,
REVERSE(SUBSTRING (@StringToReverse,
@StartPosition
LEN(@StringToReverse) - @StartPosition + 1))))
END
GO

Usage of above UDF_ReverseString:

Reversing the string from third position
SELECT dbo.UDF_ReverseString('forward string',3)
Results Set : forgnirts draw

Reversing the entire string passing 0 as beginning character
SELECT dbo.UDF_ReverseString('forward string',0)
Results Set : gnirts drawrof

Reversing the entire string passing negative number as beginning character
SELECT dbo.UDF_ReverseString('forward string',-9)
Results Set : gnirts drawrof

Reversing the entire string passing larger number than string length as beginning character
SELECT dbo.UDF_ReverseString('forward string',900)
Results Set : gnirts drawrof