Understanding Multiple Fact Tables

See if this works, though the performance is slow:

Sales By Campaign & Customer =
VAR StartDate =
    CALCULATE (
        MAX ( 'Campaign Table'[Start Date] ),
        ALLEXCEPT ( 'Campaign Table', 'Campaign Table'[CampaignID] )
    )
VAR StartKey =
    INT ( DAY ( StartDate ) & MONTH ( StartDate ) & YEAR ( StartDate ) )
VAR EndDate =
    CALCULATE (
        MAX ( 'Campaign Table'[End Date] ),
        ALLEXCEPT ( 'Campaign Table', 'Campaign Table'[CampaignID] )
    )
VAR EndKey =
    INT ( DAY ( EndDate ) & MONTH ( EndDate ) & YEAR ( EndDate ) )
RETURN
    CALCULATE (
        [Sum Sales],
        CROSSFILTER ( 'Campaign Table'[Customer Code], 'Customer Table'[Customer Code], BOTH ),
        FILTER (
            ALL ( 'Sales Table'[DateKey] ),
            'Sales Table'[DateKey] >= StartKey
                && 'Sales Table'[DateKey] <= EndKey
        )
    )

I've attached the sample PBIX file

Hi,

My approach would be to write a calculated column formula in the Campaign Table to get the Amount from the Fact- Sales Orders Table.  For this we will have to first convert the DateKey column into an actual date column (the way dates are in the Campaign table).  Once we have the Amount column in the Campaign table, we just have to write a simple SUM measure.

Are you OK with this approach.