Intervall between dates in two diffrent tables, should I concatenate or how to do it?
I have several tables linked with diffrent keys to a facttable. Two of the tables, we can call them, Order and Delivery holds dates and many common fields like CustomID, CaseID, OfficeDepartment etc. I would like to know how many days from Order to Delivery and the also avg days. The Deliverytable holds a statusfield (status = 1, 2, 4 ...) that the avg days should reflect.
How is this best done? Should I concatenate them(or use join/left join etc) into one table i the tranforms step or link them throgh the facttable in the finally load? I´m not so in to the diffrenses between join/left join and concatenate so I can´t clearly see how I should do.