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How to check Danish personal number

CREATEFUNCTION dbo.fnCheckDanSSN ( @SSN CHAR(10) ) RETURNSBIT AS BEGIN IF @SSN NOT LIKE '[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]' RETURN 0 DECLARE @x CHAR(6) SET @x = SUBSTRING(@SSN, 5, 2) + SUBSTRING(@SSN, 3, 2) + SUBSTRING(@SSN, 1, 2) IF SUBSTRING(@SSN, 7, 1) IN('0', '1', '2', '3') AND ISDATE('19' + @x) = 0 RETURN 0 IF SUBSTRING(@SSN, 7, 1) IN('4', '9') SUBSTRING(@SSN, 5, 2) BETWEEN '00' AND '36' AND ISDATE('20' + @x) = 0 RETURN 0 IF SUBSTRING(@SSN, 7, 1) IN('4', '9') SUBSTRING(@SSN, 5, 2) BETWEEN '37' AND '99' AND ISDATE('19' + @x) = 0 RETURN 0 IF SUBSTRING(@SSN, 7, 1) IN('5', '6', '7', '8') SUBSTRING(@SSN, 5, 2) BETWEEN '00' AND '57' AND ISDATE('20' + @x) = 0 RETURN 0 IF SUBSTRING(@SSN, 7, 1) IN('5', '6', '7', '8') SUBSTRING(@SSN, 5, 2) BETWEEN '58' AND '99' AND ISDATE('18' + @x) = 0 RETURN 0 DECLARE @Digits INT SET @Digits = 4 * SUBSTRING(@SSN, 1, 1) + 3 * SUBSTRING(@SSN, 2, 2) + 2 * SUBSTRING(@SSN, 3, 2) + 7 * SUBSTRING(@SSN, 4, 2) + 6 * SUBSTRING(@SSN, 5, 2) + 5 * SUBSTRING(@SSN, 6, 2) + 4 * SUBSTRING(@SSN, 7, 2) + 3 * SUBSTRING(@SSN, 8, 2) + 2 * SUBSTRING(@SSN, 9, 2) + 1 * SUBSTRING(@SSN, 10, 2) RETURN1 - SIGN(@Digits % 11) END Legacy Comments Saggi Neumann 2009-05-30 re: How to check Danish personal number This is how we validate ID numbers in Israel. Read more →

How to calculate Finnish personal number

CREATEFUNCTION dbo.fnCalculateFinSSN ( @SSN CHAR(10) ) RETURNSCHAR(11) AS BEGIN IF LOWER(@SSN) NOT LIKE '[0-9][0-9][0-9][0-9][0-9][0-9][-+a][0-9][0-9][0-9]' RETURN NULL IF SUBSTRING(@SSN, 7, 1) IN('-', '+') AND ISDATE('19' + SUBSTRING(@SSN, 1, 6)) = 0 RETURN NULL IF LOWER(SUBSTRING(@SSN, 7, 1)) = 'a' AND ISDATE('20' + SUBSTRING(@SSN, 1, 6)) = 0 RETURN 0 DECLARE @Digits INT SET @Digits = CAST(SUBSTRING(@SSN, 1, 6) + SUBSTRING(@SSN, 8, 3) AS INT) % 31 RETURN @@SSN + SUBSTRING('0123456789abcdefghijklmnopqrstuvwxy', @Digits + 1, 1) END Read more →

How to check Finnish personal number

CREATEFUNCTION dbo.fnCheckFinSSN ( @SSN CHAR(11) ) RETURNSBIT AS BEGIN IF LOWER(@SSN) NOT LIKE '[0-9][0-9][0-9][0-9][0-9][0-9][-+a][0-9][0-9][0-9][0-9a-y]' RETURN 0 IF SUBSTRING(@SSN, 7, 1) IN('-', '+') AND ISDATE('19' + SUBSTRING(@SSN, 1, 6)) = 0 RETURN 0 IF LOWER(SUBSTRING(@SSN, 7, 1)) = 'a' AND ISDATE('20' + SUBSTRING(@SSN, 1, 6)) = 0 RETURN 0 DECLARE @Digits INT SET @Digits = CAST(SUBSTRING(@SSN, 1, 6) + SUBSTRING(@SSN, 8, 3) AS INT) % 31 IF SUBSTRING('0123456789abcdefghijklmnopqrstuvwxy', @Digits + 1, 1) <> LOWER(RIGHT(@SSN, 1)) SET@Digits = -1 RETURN @Digits + 1 END Read more →

Extended ISO week function

CREATEFUNCTION dbo.fnISOWEEK ( @theDate DATETIME ) RETURNSTINYINT AS BEGIN RETURN ( SELECT CASE WHEN @theDate >= '99990104' THEN (DATEPART(DAYOFYEAR, @theDate) - 4) / 7 WHEN @theDate >= '99990101' THEN 52 WHEN NextYear <= @theDate THEN 0 WHEN CurrentYear <= @theDate THEN DATEDIFF(DAY, CurrentYear, @theDate) / 7 ELSE DATEDIFF(DAY, PreviousYear, @theDate) / 7 END + 1 FROM ( SELECT DATEADD(DAY,(DATEDIFF(DAY, '17530101', DATEADD(YEAR, -1, Jan4)) / 7) * 7, '17530101') AS PreviousYear, DATEADD(DAY,(DATEDIFF(DAY, '17530101', Jan4) / 7) * 7, '17530101') AS CurrentYear, DATEADD(DAY,(DATEDIFF(DAY, '17530101', DATEADD(YEAR, 1, Jan4)) / 7) * 7, '17530101') AS NextYear FROM ( SELECT DATEADD(YEAR, DATEDIFF(YEAR, 0, @theDate), 3) AS Jan4 )AS x ) AS d ) END Read more →

Greatest Common Divisor function

This approach is not dependent on the 32-level recursion as most other algorithms are for this problem. CREATEFUNCTION dbo.fnGCD ( @a INT, @b INT ) RETURNSINT AS BEGIN DECLARE @c INT IF @a IS NULL OR @b IS NULL OR (@a = 0 AND @b = 0) RETURN NULL IF @a = 0 OR @b = 0 RETURN ABS(@a) + ABS(@b) IF ABS(@a) < ABS(@b) SELECT @c = ABS(@a), @a = ABS(@b), @b = @c ELSE SELECT @a = ABS(@a), @b = ABS(@b) SET @c = @a % @b WHILE @c > 0 SELECT @a = @b, @b = @c, @c = @a % @b RETURN @b END Legacy Comments RBarryYoung 2009-04-15 re: Greatest Common Divisor function That's the iterative version of the chinese remainder algorithim, isn't it Peso? Read more →

Composable DML

With the arrival of SQL Server 2005 the new OUTPUT operator was introduced. The OUTPUT operator works much like a "local trigger" on the current statement. The drawback is that there is no way to filter the returned resultset directly. Read more →

Excel DAYS360 clone

CREATEFUNCTION dbo.DATEDIFF360 ( @source DATETIME, @target DATETIME, @style BIT = 0 ) RETURNSINT AS BEGIN RETURNCASE @style -- European style WHEN 1 THENCASE WHEN DATEPART(DAY, @target) = 31 THEN 30 ELSE DATEPART(DAY, @target) END - CASE WHEN DATEPART(DAY, @source) = 31 THEN 30 ELSE DATEPART(DAY, @source) END -- US style ELSECASE WHEN DATEPART(DAY, @target) = 31 AND DATEPART(DAYOFYEAR, @source) = 60 AND DATEPART(MONTH, @source) = 2 THEN 30 WHEN DATEPART(DAY, @target) = 31 AND DATEPART(DAY, @source) < 30 THEN 31 WHEN DATEPART(DAY, @target) = 31 THEN 30 ELSE DATEPART(DAY, @target) END - CASE WHEN @source = DATEADD(MONTH, DATEDIFF(MONTH, -1, @source), -1) THEN 30 ELSE DATEPART(DAY, @source) END END + 30 * DATEDIFF(MONTH, @source, @target) END Read more →

Excel ERF clone for two variables

I previously posted a solution for one variable here http://weblogs.sqlteam.com/peterl/archive/2009/03/11/Excel-ERF-clone.aspx and here is a solution for using two variables. CREATEFUNCTION dbo.fnErf ( @z1 FLOAT, @z2 FLOAT, @MaxIterations TINYINT = 10 ) RETURNSFLOAT AS BEGIN IF @z1 IS NULL OR @z2 IS NULL RETURN NULL DECLARE @n TINYINT, @s1 FLOAT, @s2 FLOAT, @p1 FLOAT, @p2 FLOAT, @a1 FLOAT, @a2 FLOAT SELECT @n = 1, @p1 = 1, @p2 = 1, @a1 = @z1, @a2 = @z2, @MaxIterations = COALESCE(ABS(@MaxIterations), 10) WHILE @p1 <> 0. Read more →

Competition

Adam Machanic has a nice competition going on here http://sqlblog.com/blogs/adam_machanic/archive/2009/02/27/t-sql-challenge-grouped-string-concatenation.aspx until the 16th of March 2009. Please join in! The prize, for the best submission, is a full MSDN subscription, valued at around $10,000. Read more →