Tableau - Blend Multiple Tableau Server Data Sources

Question

I have three Tableau Server data sources in a workbook that represent three tables in a database. Table A is joined to Table B and table B is joined to Table C. There is no foreign key relationship between Table A and Table C, but the implicit relationship exists through Table B (junction table). When using Table A as the primary data source on a report, I receive an error message when attempting to add data from Table C.

In order to use fields from Table C, a relationship needs to be created with Table A. Select Data > Edit Relationships to open the Relationships dialog box.

Is there any way to join multiple Tableau Server data sources to accomplish the described scenario?

Answer 1

Tableau has the concept of Primary and Secondary data sources, and every secondary needs to have a key into the primary to be considered. You can't link a secondary to a secondary data source.

My suggestion here would be creating another data source already joined/blended. This can be done by connecting directly to the database and joining the tables using Tableau wizard (see image below):

Or, if you feel comfortable, you can use the New Custom SQL button and use your own query (see image below):