T-SQL Start and end date times from a single column

Question

I have a single table of on/off events for different assets. I need to get a list of start & stop event times without using a cursor.

Source:

Item          


        

Answer 1

Untested...

;WITH myCTE AS
(
   SELECT *,
         ROW_NUMBER() OVER (PARTITION BY Item ORDER BY EventDate) AS rn
   FROM MyTable
)
SELECT
   M1.Item,
   M1.EventDate AS Start,
   M2.EventDate AS End
FROM
   myCTE M1
   JOIN
   myCTE M2 ON M1.Item = M2.Item AND M1.rn+1 = M2.rn
WHERE
   M1.Event = 'On'
   AND
   M2.Event = 'Off';