위의 로직을 발견..
상당히 괜찮다!!
SELECT [dbo].[GetPercentageOfTwoStringMatching]('valentin123456' ,'valnetin123456')
CREATE FUNCTION [dbo].[GetPercentageOfTwoStringMatching]
(
@string1 NVARCHAR(100)
,@string2 NVARCHAR(100)
)
RETURNS INT
AS
BEGIN
DECLARE @levenShteinNumber INT
DECLARE @string1Length INT = LEN(@string1)
, @string2Length INT = LEN(@string2)
DECLARE @maxLengthNumber INT = CASE WHEN @string1Length > @string2Length THEN @string1Length ELSE @string2Length END
SELECT @levenShteinNumber = [dbo].[LEVENSHTEIN] ( @string1 ,@string2)
DECLARE @percentageOfBadCharacters INT = @levenShteinNumber * 100 / @maxLengthNumber
DECLARE @percentageOfGoodCharacters INT = 100 - @percentageOfBadCharacters
-- Return the result of the function
RETURN @percentageOfGoodCharacters
END
-- =============================================
-- Create date: 2011.12.14
-- Description: http://blog.sendreallybigfiles.com/2009/06/improved-t-sql-levenshtein-distance.html
-- =============================================
CREATE FUNCTION [dbo].[LEVENSHTEIN](@left VARCHAR(100),
@right VARCHAR(100))
returns INT
AS
BEGIN
DECLARE @difference INT,
@lenRight INT,
@lenLeft INT,
@leftIndex INT,
@rightIndex INT,
@left_char CHAR(1),
@right_char CHAR(1),
@compareLength INT
SET @lenLeft = LEN(@left)
SET @lenRight = LEN(@right)
SET @difference = 0
IF @lenLeft = 0
BEGIN
SET @difference = @lenRight
GOTO done
END
IF @lenRight = 0
BEGIN
SET @difference = @lenLeft
GOTO done
END
GOTO comparison
COMPARISON:
IF ( @lenLeft >= @lenRight )
SET @compareLength = @lenLeft
ELSE
SET @compareLength = @lenRight
SET @rightIndex = 1
SET @leftIndex = 1
WHILE @leftIndex <= @compareLength
BEGIN
SET @left_char = substring(@left, @leftIndex, 1)
SET @right_char = substring(@right, @rightIndex, 1)
IF @left_char <> @right_char
BEGIN -- Would an insertion make them re-align?
IF( @left_char = substring(@right, @rightIndex + 1, 1) )
SET @rightIndex = @rightIndex + 1
-- Would an deletion make them re-align?
ELSE IF( substring(@left, @leftIndex + 1, 1) = @right_char )
SET @leftIndex = @leftIndex + 1
SET @difference = @difference + 1
END
SET @leftIndex = @leftIndex + 1
SET @rightIndex = @rightIndex + 1
END
GOTO done
DONE:
RETURN @difference
END