how to find time interval between the datetime on the row and the previous row

[tparvaiz]

Hi, I have a table that looks like this. (Sorted by City and then by Order Completion Time)

City	Order No	Order Completion Time	Time between Order Processing (Mints)
Toronto	1	18APR2017:00:50:00.000
Toronto	2	18APR2017:01:07:00.000	17
Toronto	3	18APR2017:01:50:00.000	43
Toronto	4	18APR2017:02:44:00.000	54
Toronto	5	18APR2017:03:15:00.000	31
Toronto	6	18APR2017:03:55:00.000	40

Now I want to calculate  "Time Between Order Processing" which is simply the time of the order minus time of the previous order.

can you please advise how to do it

[Reeza · Accepted solution]

Look up the LAG or DIF functions. 

[tparvaiz]

Thank you