I'm new to tableau and am having trouble with something I thought would be quite easy. I have a table (live connection to an excel file) which includes customer numbers and their pricing tiers. In another table (another excel file) I have web usage stats tied to a customer number (though a single customer could be listed multiple times). I've tied the two together with customer number and want to create a report showing the usage by tier. When I pull in tier and then a usage field I get a warning saying "Cannot blend aggregated data from the secondary data source with the data on this sheet because there are no linking fields used in the view". So does this mean I need to include customer number in the report (to set up the link) but then is there a way to hide it and allow the data to roll up into the tiers? This would be fairly simple in Access but I wanted to learn tableau but I'm confused by what I'm clearing missing here.