Hi,

Attached is a script to build the tables with data.

(rename to .sql of course).

I tried to do for the start something like:

SELECT Unit.Name, Unit.SerialNumber, Unit.Location, UD.PowerConsumptionValue, LastDate

FROM Units Unit

CROSS APPLY (

SELECT TOP 1 UD.PowerConsumptionValue, MAX(UD.DateOfData) AS LastDate

FROM UnitsData UD

WHERE Unit.ID = UD.UnitID

GROUP BY UD.PowerConsumptionValue

ORDER BY LastDate DESC

) UD

But it returns to me only one unit and not the others.

Appreciate your kindly help.

Thanks