Warning: Cannot Blend Because No Linking Fields

When you drag a field from a secondary data source to the view, you may see a warning that says:

Cannot blend aggregated data from the secondary data source with the data on this sheet becuase there are no linking fields used in the view.

This warning occurs when you have not used a linking field in the view. For example, if you have two data sources with the related dimensions State and Date, you must be using one of those primay dimensions in the view before you can blend data from the secondary data source.

The secondary data source may not have any relationships to the primary data source. Look in the Data window for the link icon. Tableau automatically links fields that have the same name. If your fields do not have the same name you’ll have to create a custom relationship. Refer to Defining Relationships.