SQL calaulate start time and end time between a date range

I need to calculate a start and end time between a date range.   This gives the date range and the different times.  I need Patient.AnesStartTime and Patient.EndStartTime calculated to show how much time for each patient between the date range.

SELECT     AnesStaff.AnesLastName, AnesStaff.AnesFirstName, Service.Service, Service.MEPERSCode, AnesStaff.FlagRelief, Patient.DateSurgery, Patient.AnesStartTime,
FROM         Service INNER JOIN
                      AnesStaff ON Service.PatientID = AnesStaff.PatientID INNER JOIN
                      Patient ON Service.PatientID = Patient.PatientID AND AnesStaff.PatientID = Patient.PatientID
WHERE     (Patient.DateSurgery BETWEEN CONVERT(DATETIME, '2008-03-01 00:00:00', 102) AND CONVERT(DATETIME, '2008-04-01 00:00:00', 102))

Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

ste5anSenior DeveloperCommented:
hmm, DateSurgery should be a DATE, not DATETIME. AnesStartTime and AnesEndTime should be TIME. You need to check whether constraints exists on these columns to ensure their domain. Otherwise you may get wrong results.

When to model is ok, then you simply use DATEDIFF() to calculate a [DATE]TIME difference.

SELECT  AnS.AnesLastName ,
        AnS.AnesFirstName ,
        S.Service ,
        S.MEPERSCode ,
        AnS.FlagRelief ,
        P.DateSurgery ,
        P.AnesStartTime ,
        P.AnesEndTime ,
        DATEDIFF(MINUTE, P.AnesStartTime, P.AnesEndTime) AS AnesTimeDifferenceInM
FROM    [Service] S
        INNER JOIN AnesStaff AnS ON S.PatientID = AnS.PatientID
        INNER JOIN Patient P ON S.PatientID = P.PatientID
                                AND AnS.PatientID = P.PatientID
WHERE   P.DateSurgery BETWEEN '20080301' AND '20080401';

Open in new window

Caveat: The result of DATEDIFF() is a date/time range. There is no built-in data type nor formatting in SQL Server. Thus the result is an integer in the chosen resolution (here minutes).

p.s. use always table alias names. It increases readability.

p.p.s. instead of using CONVERT() on constants, use an unambiguous date literal like 'yyyymmdd'.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
JohnMac328Author Commented:
Thanks that seems to work.  I agree with your statements but this is a deployed system and those changes are not allowed since it has been sunsetted.  I have seen other reports with the times displaying like your example shows.  Reports are still allowed.
JohnMac328Author Commented:
Thanks again
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Query Syntax

From novice to tech pro — start learning today.