How to Calculate longest streak in SQL?

Posted by VJ on Stack Overflow See other posts from Stack Overflow or by VJ
Published on 2010-06-15T22:38:03Z Indexed on 2010/06/15 22:42 UTC
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tsql

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sql-server-2008

I have

EMPLOYEE-ID,DATE,IsPresent

I want to calculate longest streak for a employee presence.The Present bit will be false for days he didnt come..So I want to calculate the longest number of days he came to office for consecutive dates..I have the Date column field is unique...So I tried this way -

Select Id,Count(*) from Employee where IsPresent=1

But the above doesnt work...Can anyone guide me towards how I can calculate streak for this?....I am sure people have come across this...I tried searching online but...didnt understand it well...please help me out..

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