DataScramble - Randomizing data rows

Before:
           StudentID   StudentName          DateOfBirth
           ----------- -------------------- -------------
           1           John Smith           1990-03-21
           2           Fred Bloggs          1988-11-02
           3           Another User         1985-07-11
           4           Yet Another User     1977-06-25

       After:
           StudentID   StudentName          DateOfBirth
           ----------- -------------------- -------------
           1           PDUHjRWJcb           1926-01-02
           2           WRmNqQKxvuV          1969-03-14
           3           nBCkAVDrvdhe         1968-05-05
           4           RJDsFMaeNcLrcMWw     1964-08-08

1.  Before: 
2.             StudentID   StudentName          DateOfBirth 
3.             ----------- -------------------- ------------- 
4.             1           John Smith           1990-03-21 
5.             2           Fred Bloggs          1988-11-02 
6.             3           Another User         1985-07-11 
7.             4           Yet Another User     1977-06-25 
8.   
9.         After: 
10.             StudentID   StudentName          DateOfBirth 
11.             ----------- -------------------- ------------- 
12.             1           PDUHjRWJcb           1926-01-02 
13.             2           WRmNqQKxvuV          1969-03-14 
14.             3           nBCkAVDrvdhe         1968-05-05 
15.             4           RJDsFMaeNcLrcMWw     1964-08-08 

-- Drop the view if it already exists
IF OBJECT_ID ('vwRandom', 'V') IS NOT NULL
DROP VIEW vwRandom ;
GO

-- Used to reference RAND within a function
CREATE VIEW vwRandom
AS
SELECT RAND() as RandomValue;
GO

1.  -- Drop the view if it already exists 
2.  IF OBJECT_ID ('vwRandom', 'V') IS NOT NULL 
3.  DROP VIEW vwRandom ; 
4.  GO 
5.   
6.  -- Used to reference RAND within a function 
7.  CREATE VIEW vwRandom 
8.  AS 
9.  SELECT RAND() as RandomValue; 
10.  GO 

-- Drop the function if it already exists
IF OBJECT_ID ('ufn_DataScramble', 'FN') IS NOT NULL
DROP FUNCTION ufn_DataScramble ;
GO

-- Create user defined function
CREATE FUNCTION ufn_DataScramble
(
    @OrigVal varchar(max)
)
RETURNS varchar(max)
WITH ENCRYPTION
AS
BEGIN

        -- Variables used
        DECLARE @NewVal varchar(max);
        DECLARE @OrigLen int;
        DECLARE @CurrLen int;
        DECLARE @LoopCt int;
        DECLARE @Rand int;
        DECLARE @RandString varchar(max);

        -- for dates/times
        DECLARE @MinYear int;
        DECLARE @MaxYear int;
        DECLARE @RandYear int;
        DECLARE @RandMonth int;
        DECLARE @RandDay int;
        DECLARE @RandHour int;
        DECLARE @RandMinute int;
        DECLARE @RandSeconds int;
        DECLARE @RandMSeconds int;
        DECLARE @RandChar varchar(1);
        DECLARE @RandNum int;
        DECLARE @DateVal date;
        DECLARE @TimeVal time;
        DECLARE @DateMatch int;
        DECLARE @TimeMatch int;
        DECLARE @ColumnTypeIsDate int;
        DECLARE @IntOptions int;
        DECLARE @CharOptions varchar(max);

        -- Format given value (prevents CHAR datatype issue)
        SET @OrigVal = LTRIM(RTRIM(@OrigVal));

        -- Set variable default values
        SET @NewVal = '';
        SET @OrigLen = LEN(CAST(@OrigVal AS VARCHAR(max)));
        SET @CurrLen = @OrigLen;
        SET @LoopCt = 1;
        SET @DateVal = ''; -- 1900-01-01
        SET @TimeVal = ''; -- 00:00:00.000
        SET @DateMatch = 0;
        SET @TimeMatch = 0;
        SET @ColumnTypeIsDate = 0;

        -- Determine if Given Value is date
        IF @OrigVal IS NULL
                RETURN NULL;

        -- Determine if Given Value is date
        IF ISDATE(@OrigVal)=1
                SET @ColumnTypeIsDate = 1;

        -- Determine if Given Value is date (ISDATE does not recognize CAST AS DATE)
        IF @OrigLen=10
                AND (LEN(@OrigVal) - LEN(REPLACE(@OrigVal, '-', '')))=2
                AND ISNUMERIC(SUBSTRING(@OrigVal, 1, 4))=1
                AND ISNUMERIC(SUBSTRING(@OrigVal, 6, 2))=1
                AND ISNUMERIC(SUBSTRING(@OrigVal, 9, 2))=1
                SET @ColumnTypeIsDate = 1;


        -- Determine if this is a date/time value
        IF @ColumnTypeIsDate=1
        BEGIN

                -- DETERMINE IF THIS FIELD CONTAINS A DATE VALUE
                SET @DateMatch =
                        CASE
                                WHEN CAST(CAST(@OrigVal AS date) AS VARCHAR(10))'1900-01-01' THEN 1
                                ELSE 0
                        END;


                -- DETERMINE IF THIS FIELD CONTAINS A TIME VALUE
                SET @TimeMatch =
                        CASE
                                WHEN CAST(CAST(@OrigVal AS time) AS VARCHAR(10))'00:00:00.000' THEN 1
                                ELSE 0
                        END;


                -- DETERMINE TIME VALUE IF TIME WAS IN GIVEN VALUE
                IF @DateMatch=1
                BEGIN
                        -- SET YEAR RANGE (1912 - 1994: for Birthdate specifically: Older than 18 but younger than 100)
                        SET @MinYear = DATEPART(YEAR,GETDATE())-100;    -- 100 years ago from today
                        SET @MaxYear = DATEPART(YEAR,GETDATE())-18;             -- 18 years ago from today


                        -- GET RANDOM DATE VALUES
                        SELECT @RandYear = ((@MinYear + 1) - @MaxYear) * RandomValue + @MaxYear FROM dbo.vwRandom;
                        SELECT @RandMonth = (1 - 12) * RandomValue + 12 FROM dbo.vwRandom;
                        SELECT @RandDay = (1 - 28) * RandomValue + 28 FROM dbo.vwRandom;  -- prevent invalid dates (specifically 31 days in feb)
                        SET     @DateVal =
                                CAST(@RandYear AS CHAR(4)) + '-'
                                + STUFF(@RandMonth, 1, 0, REPLICATE('0', 2 - LEN(@RandMonth))) + '-'
                                + STUFF(@RandDay, 1, 0, REPLICATE('0', 2 - LEN(@RandDay)));
                END


                -- DETERMINE TIME VALUE IF TIME WAS IN GIVEN VALUE
                IF @TimeMatch=1
                BEGIN

                        -- SET RANDOM TIME VALUE (include Milliseconds)
                        SELECT @RandHour = (0 - 23) * RandomValue + 23 FROM dbo.vwRandom;
                        SELECT @RandMinute = (0 - 59) * RandomValue + 59 FROM dbo.vwRandom;
                        SELECT @RandSeconds = (0 - 59) * RandomValue + 59 FROM dbo.vwRandom;
                        SELECT @RandMSeconds = (0 - 999) * RandomValue + 999 FROM dbo.vwRandom;
                        SET @TimeVal =
                                STUFF(@RandHour, 1, 0, REPLICATE('0', 2 - LEN(@RandHour)))
                                + ':' + STUFF(@RandMinute, 1, 0, REPLICATE('0', 2 - LEN(@RandMinute)))
                                + ':' + STUFF(@RandSeconds, 1, 0, REPLICATE('0', 2 - LEN(@RandSeconds)))
                                + '.' + STUFF(@RandMSeconds, 1, 0, REPLICATE('0', 3 - LEN(@RandMSeconds)));
                        SET @TimeVal = CONVERT(time, @TimeVal, 14);

                END


                -- DETERMINE WHICH DATE PARTS WERE SUBMITTED
                IF @TimeMatch=1 AND @DateMatch=0
                        SET @NewVal = @TimeVal;
                ELSE IF @TimeMatch=0 AND @DateMatch=1
                        SET @NewVal = @DateVal;
                ELSE IF @TimeMatch=1 AND @DateMatch=1
                        SET @NewVal = CAST(@DateVal AS varchar(10)) + ' ' + CAST(@TimeVal AS varchar(16));
                ELSE
                        SET @NewVal = '';


                -- REDUCE THIS STRING TO THE SAME LENGTH AS SUBMITTED VALUE // not necessary for update
                -- SET @NewVal = SUBSTRING(LTRIM(RTRIM(CAST(@NewVal AS VARCHAR(30)))), 1, LEN(@OrigVal));

        END
        ELSE
        BEGIN

                    IF ISNUMERIC(@OrigVal)=1
                    BEGIN

                        SET @NewVal = '';

                                -- Loop through the characters passed
                                WHILE @LoopCt

1.  -- Drop the function if it already exists 
2.  IF OBJECT_ID ('ufn_DataScramble', 'FN') IS NOT NULL 
3.  DROP FUNCTION ufn_DataScramble ; 
4.  GO 
5.   
6.  -- Create user defined function 
7.  CREATE FUNCTION ufn_DataScramble 
8.  ( 
9.      @OrigVal varchar(max) 
10.  ) 
11.  RETURNS varchar(max) 
12.  WITH ENCRYPTION 
13.  AS 
14.  BEGIN 
15.   
16.          -- Variables used 
17.          DECLARE @NewVal varchar(max); 
18.          DECLARE @OrigLen int; 
19.          DECLARE @CurrLen int; 
20.          DECLARE @LoopCt int; 
21.          DECLARE @Rand int; 
22.          DECLARE @RandString varchar(max); 
23.   
24.          -- for dates/times 
25.          DECLARE @MinYear int; 
26.          DECLARE @MaxYear int; 
27.          DECLARE @RandYear int; 
28.          DECLARE @RandMonth int; 
29.          DECLARE @RandDay int; 
30.          DECLARE @RandHour int; 
31.          DECLARE @RandMinute int; 
32.          DECLARE @RandSeconds int; 
33.          DECLARE @RandMSeconds int; 
34.          DECLARE @RandChar varchar(1); 
35.          DECLARE @RandNum int; 
36.          DECLARE @DateVal date; 
37.          DECLARE @TimeVal time; 
38.          DECLARE @DateMatch int; 
39.          DECLARE @TimeMatch int; 
40.          DECLARE @ColumnTypeIsDate int; 
41.          DECLARE @IntOptions int; 
42.          DECLARE @CharOptions varchar(max); 
43.   
44.          -- Format given value (prevents CHAR datatype issue) 
45.          SET @OrigVal = LTRIM(RTRIM(@OrigVal)); 
46.   
47.          -- Set variable default values 
48.          SET @NewVal = ''; 
49.          SET @OrigLen = LEN(CAST(@OrigVal AS VARCHAR(max))); 
50.          SET @CurrLen = @OrigLen; 
51.          SET @LoopCt = 1; 
52.          SET @DateVal = ''; -- 1900-01-01 
53.          SET @TimeVal = ''; -- 00:00:00.000 
54.          SET @DateMatch = 0; 
55.          SET @TimeMatch = 0; 
56.          SET @ColumnTypeIsDate = 0; 
57.   
58.          -- Determine if Given Value is date 
59.          IF @OrigVal IS NULL 
60.                  RETURN null; 
61.   
62.          -- Determine if Given Value is date 
63.          IF ISDATE(@OrigVal)=1 
64.                  SET @ColumnTypeIsDate = 1; 
65.   
66.          -- Determine if Given Value is date (ISDATE does not recognize CAST AS DATE) 
67.          IF @OrigLen=10 
68.                  AND (LEN(@OrigVal) - LEN(REPLACE(@OrigVal, '-', '')))=2 
69.                  AND ISNUMERIC(SUBSTRING(@OrigVal, 1, 4))=1 
70.                  AND ISNUMERIC(SUBSTRING(@OrigVal, 6, 2))=1 
71.                  AND ISNUMERIC(SUBSTRING(@OrigVal, 9, 2))=1 
72.                  SET @ColumnTypeIsDate = 1; 
73.   
74.   
75.          -- Determine if this is a date/time value 
76.          IF @ColumnTypeIsDate=1 
77.          BEGIN 
78.   
79.                  -- DETERMINE IF THIS FIELD CONTAINS A DATE VALUE 
80.                  SET @DateMatch = 
81.                          CASE 
82.                                  WHEN CAST(CAST(@OrigVal AS date) AS VARCHAR(10))'1900-01-01' THEN 1 
83.                                  ELSE 0 
84.                          END; 
85.   
86.   
87.                  -- DETERMINE IF THIS FIELD CONTAINS A TIME VALUE 
88.                  SET @TimeMatch = 
89.                          CASE 
90.                                  WHEN CAST(CAST(@OrigVal AS time) AS VARCHAR(10))'00:00:00.000' THEN 1 
91.                                  ELSE 0 
92.                          END; 
93.   
94.   
95.                  -- DETERMINE TIME VALUE IF TIME WAS IN GIVEN VALUE 
96.                  IF @DateMatch=1 
97.                  BEGIN 
98.                          -- SET YEAR RANGE (1912 - 1994: for Birthdate specifically: Older than 18 but younger than 100) 
99.                          SET @MinYear = DATEPART(YEAR,GETDATE())-100;    -- 100 years ago from today 
100.                          SET @MaxYear = DATEPART(YEAR,GETDATE())-18;             -- 18 years ago from today 
101.   
102.   
103.                          -- GET RANDOM DATE VALUES 
104.                          SELECT @RandYear = ((@MinYear + 1) - @MaxYear) * RandomValue + @MaxYear FROM dbo.vwRandom; 
105.                          SELECT @RandMonth = (1 - 12) * RandomValue + 12 FROM dbo.vwRandom; 
106.                          SELECT @RandDay = (1 - 28) * RandomValue + 28 FROM dbo.vwRandom;  -- prevent invalid dates (specifically 31 days in feb) 
107.                          SET     @DateVal = 
108.                                  CAST(@RandYear AS CHAR(4)) + '-' 
109.                                  + STUFF(@RandMonth, 1, 0, REPLICATE('0', 2 - LEN(@RandMonth))) + '-' 
110.                                  + STUFF(@RandDay, 1, 0, REPLICATE('0', 2 - LEN(@RandDay))); 
111.                  END 
112.   
113.   
114.                  -- DETERMINE TIME VALUE IF TIME WAS IN GIVEN VALUE 
115.                  IF @TimeMatch=1 
116.                  BEGIN 
117.   
118.                          -- SET RANDOM TIME VALUE (include Milliseconds) 
119.                          SELECT @RandHour = (0 - 23) * RandomValue + 23 FROM dbo.vwRandom; 
120.                          SELECT @RandMinute = (0 - 59) * RandomValue + 59 FROM dbo.vwRandom; 
121.                          SELECT @RandSeconds = (0 - 59) * RandomValue + 59 FROM dbo.vwRandom; 
122.                          SELECT @RandMSeconds = (0 - 999) * RandomValue + 999 FROM dbo.vwRandom; 
123.                          SET @TimeVal = 
124.                                  STUFF(@RandHour, 1, 0, REPLICATE('0', 2 - LEN(@RandHour))) 
125.                                  + ':' + STUFF(@RandMinute, 1, 0, REPLICATE('0', 2 - LEN(@RandMinute))) 
126.                                  + ':' + STUFF(@RandSeconds, 1, 0, REPLICATE('0', 2 - LEN(@RandSeconds))) 
127.                                  + '.' + STUFF(@RandMSeconds, 1, 0, REPLICATE('0', 3 - LEN(@RandMSeconds))); 
128.                          SET @TimeVal = CONVERT(time, @TimeVal, 14); 
129.   
130.                  END 
131.   
132.   
133.                  -- DETERMINE WHICH DATE PARTS WERE SUBMITTED 
134.                  IF @TimeMatch=1 AND @DateMatch=0 
135.                          SET @NewVal = @TimeVal; 
136.                  ELSE IF @TimeMatch=0 AND @DateMatch=1 
137.                          SET @NewVal = @DateVal; 
138.                  ELSE IF @TimeMatch=1 AND @DateMatch=1 
139.                          SET @NewVal = CAST(@DateVal AS varchar(10)) + ' ' + CAST(@TimeVal AS varchar(16)); 
140.                  ELSE 
141.                          SET @NewVal = ''; 
142.   
143.   
144.                  -- REDUCE THIS STRING TO THE SAME LENGTH AS SUBMITTED VALUE // not necessary for update 
145.                  -- SET @NewVal = SUBSTRING(LTRIM(RTRIM(CAST(@NewVal AS VARCHAR(30)))), 1, LEN(@OrigVal)); 
146.   
147.          END 
148.          ELSE 
149.          BEGIN 
150.   
151.                      IF ISNUMERIC(@OrigVal)=1 
152.                      BEGIN 
153.   
154.                          SET @NewVal = ''; 
155.   
156.                                  -- Loop through the characters passed 
157.                                  WHILE @LoopCt