Create Date Ranges for Consecutive dates in a SQL Server Table

I had recently posted a SQL script to SQL Query to Find out who attended office on Saturday

Shashi commented asking it was possible to create Date Range for all consecutive dates and group them together in such queries. Here is a query to group all the consecutive dates together and create a range out of them.

SAMPLE DATA

DECLARE @TT TABLE (EID int, CheckIn DATETIME)
INSERT INTO @TT VALUES (2, 'April 02, 2010 11:25am')
INSERT INTO @TT VALUES (4, 'April 03, 2010 9:55am')
INSERT INTO @TT VALUES (5, 'April 07, 2010 11:24am')
INSERT INTO @TT VALUES (2, 'April 10, 2010 11:22am')
INSERT INTO @TT VALUES (3, 'April 15, 2010 5:27am')
INSERT INTO @TT VALUES (6, 'April 16, 2010 8:21am')
INSERT INTO @TT VALUES (7, 'April 17, 2010 11:55am')
INSERT INTO @TT VALUES (3, 'April 22, 2010 10:16am')
INSERT INTO @TT VALUES (4, 'April 24, 2010 11:35am')
INSERT INTO @TT VALUES (7, 'April 30, 2010 9:49pm')
INSERT INTO @TT VALUES (2, 'May 01, 2010 9:49am')
INSERT INTO @TT VALUES (5, 'May 02, 2010 10:43am')
INSERT INTO @TT VALUES (3, 'May 03, 2010 11:29am')

QUERY

SELECT MIN(CheckIn) AS BeginRange,
       MAX(CheckIn) AS EndRange
FROM (
SELECT CheckIn,
    DATEDIFF(D, ROW_NUMBER() OVER(ORDER BY CheckIn), CheckIn) AS DtRange
FROM @TT) AS dt
GROUP BY DtRange;

OUTPUT

About The Author

Suprotim Agarwal, MCSD, MCAD, MCDBA, MCSE, is the founder of DotNetCurry, DNC Magazine for Developers, SQLServerCurry and DevCurry. He has also authored a couple of books 51 Recipes using jQuery with ASP.NET Controls and a new one recently at The Absolutely Awesome jQuery CookBook.

Suprotim has received the prestigous Microsoft MVP award for nine times in a row now. In a professional capacity, he is the CEO of A2Z Knowledge Visuals Pvt Ltd, a digital group that represents premium web sites and digital publications comprising of Professional web, windows, mobile and cloud developers, technical managers, and architects.

Get in touch with him on Twitter @suprotimagarwal, LinkedIn or befriend him on Facebook