try a pivot table if values are coming in different lines. how are you adding the values?
You never "join" fact tables together but you use them across their conformed dimensionalities surrounding them.
Christian Berg is correct - we don't join two fact tables
Creatively, we can. Create a second alias of one of the facts and use it as the 'conformed' dimension across both fact tables. This creates the 'star' you need. Not pretty, but it will do. Better to use a truly conformed dimension to naturally achieve the star.
You understood you must not join join 2 fact tables together ....
When you say "sum of the values" do you mean a UNION maybe to have the sum on Col1 of Table1 together with Col2 of Table2 ? (not a join at all, it's a different kind of operation)
in my understanding he was trying to union two criterias and got data in two layers. But anyhow author is no more interested in the content .. why should we ?