Question

Question on ODBC functions:

I need to get the ISO 8601 calendar week from a SQL datetime.
In SQL-Server, the syntax for that is this:

SELECT DATEPART(ISO_WEEK, GETDATE()) 

in SQL server 2005, ISO_WEEK doesn’t exist, so I have to use a function like this:
http://blogs.lessthandot.com/index.php/DataMgmt/DataDesign/iso-week-in-sql-server

Now my question:
In order to keep it database-independant,
is it possible to get the ISO-calendar week via a ODBC function ?

ODBC-Functions like this (except getdate of course):

SELECT 
 GETDATE() AS vT_SQL_DateTime_NonDeterministic_Function 

,{ fn NOW() } AS vODBC_DateTime_Canonical_Function 
,{ fn CURDATE() } AS vODBC_DateOnly_Canonical_Function 
,CAST(FLOOR(CAST(GETDATE() AS float)) AS datetime) AS vFloor_Mine 
,CONVERT(char(8),  { fn NOW() }, 112) AS v112_ISO 
,CONVERT(char(10), { fn NOW() }, 104) AS v104_Thomas 
,{ fn CONVERT({fn CURDATE()}, SQL_DATE)} AS vODBC_Proper 

-- Testing ODBC functions & syntax
,{ fn CONCAT('abc', 'def')} AS ODBC_Concat
,{ fn CONCAT(NULL, 'def')}  AS ODBC_Concat_NullLeft
,{ fn CONCAT('abc', NULL)}  AS ODBC_Concat_NullRight
,{ fn CONCAT(NULL, NULL)}   AS ODBC_Concat_NullBoth
,{ fn LENGTH('abc')}    AS ODBC_Length
,{ fn UCASE('abc')} AS ODBC_UCASE
,{ fn LCASE('ABC')} AS ODBC_LCASE
,{ fn SUBSTRING('Test me', 1, 4)} AS ODBC_SUBSTRING 
,{ fn LOCATE('in', 'needle in the haystack')}  AS ODBC_Locate 
,{ fn SUBSTRING('Test me', 1, { fn LOCATE(' me', 'Test me') } - 1)} AS ODBC_SUBSTRING_Locate

Answer 1

Edit: (by question asker)
And this is the resulting ODBC equivalent, which is the actual answer to my question:

({fn DAYOFYEAR({fn TIMESTAMPDIFF(SQL_TSI_DAY, 0, dt) } / 7 * 7 + 3)}+6) / 7 AS ODBC_ISO_WEEK

— End Edit

Here is a better way to get iso_week in sql-server 2005 or 2000

CREATE function f_isoweek(@date datetime) 
RETURNS INT 
as 
BEGIN 

RETURN (datepart(DY, datediff(d, 0, @date) / 7 * 7 + 3)+6) / 7 

END 

Read more here:

Isoweek in SQL Server 2005

EDIT: After someone claimed my script failed, i added this script proves that it works:

--This script will run on mssql server 2008, 
--it will show all rows where isoweek is calculated wrong with the given formular (0 rows)

;with a as
(
select cast('1900-01-01' as datetime) d
union all
select dateadd(day, 1, d) from a
where d < '2100-01-01'
)
select count(*) 
from a 
where (datepart(DY, datediff(d, 0, d) / 7 * 7 + 3)+6) / 7
<> datepart(iso_week, d)
option (maxrecursion 0)