Calculating total time excluding overlapped time & breaks in SQLServer

Question

From the list of start time and end times from a select query, I need to find out the total time excluding overlapping time and breaks.

StartTime                         


        

Answer 1

To get the result with the data you gave, I assume that the end time is not included (otherwise it would be 91 minutes for the first run). With that in mind, this will give you the result you want with no cursors or loops. If the times span multiple days, the logic will need to be adjusted.

--Create sample data
CREATE TABLE TimesToCheck
    ([StartTime] datetime, [EndTime] datetime)
;

INSERT INTO TimesToCheck
    ([StartTime], [EndTime])
VALUES
    ('2014-10-01 10:30:00', '2014-10-01 12:00:00'),
    ('2014-10-01 10:40:00', '2014-10-01 12:00:00'),
    ('2014-10-01 10:42:00', '2014-10-01 12:20:00'),
    ('2014-10-01 10:40:00', '2014-10-01 13:00:00'),
    ('2014-10-01 10:44:00', '2014-10-01 12:21:00'),
    ('2014-10-13 15:50:00', '2014-10-13 16:00:00')
;--Now the solution.  
;WITH
  E1(N) AS (
            SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
            SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
            SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
           ),                          -- 1*10^1 or 10 rows
  E2(N) AS (SELECT 1 FROM E1 a, E1 b), -- 1*10^2 or 100 rows
  E4(N) AS (SELECT 1 FROM E2 a, E2 b), -- 1*10^4 or 10,000 rows
  N AS  (SELECT TOP (3600) ROW_NUMBER() OVER (ORDER BY (SELECT NULL))-1 AS Number FROM E4),
  TimeList AS (SELECT CAST(DATEADD(minute,n.number,0) as time) AS m FROM N), 
  --We really only need the Timelist table.  If it is already created, we can start here.
  ActiveTimes AS (SELECT DISTINCT t.m FROM TimeList T
    INNER JOIN TimesToCheck C ON t.m BETWEEN CAST(c.StartTime as time) AND CAST(DATEADD(minute,-1,c.EndTime) as time))
  SELECT COUNT(*) FROM ActiveTimes