select  currow.ItemId,
        ( select    max(PriceStartDate)
          from      PriceHistory phPrev
          where     phPrev.PriceStartDate < currow.PriceStartDate
			and phPrev.ItemId=currow.ItemId 
        ) as OldPrice,
        currow.PriceStartDate,
        currow.Price
from    PriceHistory currow

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