hmmm, yes based on that i have come up with a simple sub-select approach:

select * from SELECT DailyMileageID, MileageAtStartOfShift, MileageAtEndOfShift, MileageAtEndOfShift - MileageAtStartOfShift AS DayMileage, MileageAtEndOfShift -

(SELECT MileageAtStartOfShift

FROM dbo.DailyMileages AS I

WHERE (DailyMileageID = b.DailyMileageID + 1)) AS NightMileage, ShopID, DateEntered

FROM dbo.DailyMileages AS b

which works, but i am a little bothered about performance, but yes, thanks for the tip :

next task... convince this company to upgrade their sql server 😀