Differenza di date

USE tempdb;
GO

CREATE TABLE dbo.Dates(
Data_In datetime NOT NULL,
Data_Out datetime NOT NULL
);
GO

INSERT dbo.Dates VALUES('20060725 14:49:57.623', '20060725 15:59:57.343');
INSERT dbo.Dates VALUES('20060725 15:59:58.323', '20060725 16:03:57.343');
GO

SELECT 
      Data_Out - Data_In AS DateDifference
    , CONVERT(char(12), Data_Out - Data_In, 114) AS DateDifferenceFormatted
FROM dbo.Dates;
GO

/* Output:

DateDifference           DateDifferenceFormatted 
------------------------ ----------------------- 
1900-01-01 01:09:59.720  01:09:59:720
1900-01-01 00:03:59.020  00:03:59:020

(2 row(s) affected)

*/

DROP TABLE dbo.Dates;

USE tempdb;
GO

CREATE TABLE dbo.Dates(
Data_In datetime NOT NULL,
Data_Out datetime NOT NULL
);
GO

INSERT dbo.Dates VALUES('20060803 14:49:57.623', '20060804 15:59:57.343');
INSERT dbo.Dates VALUES('20060803 15:59:58.323', '20060805 16:03:57.343');
GO

SELECT 
          CONVERT(char(24), Data_Out - Data_In, 113) AS DateDifferenceFormatted
FROM dbo.Dates;
GO

/* Output:

DateDifferenceFormatted 
----------------------- 
02 Jan 1900  01:09:59:720
03 Jan 1900  00:03:59:020

(2 row(s) affected)

*/

DROP TABLE dbo.Dates;