Creating Complex Joins In Your Data Source - Tableau in Two Minutes

In this video, we demonstrate how you can create complex joins with multiple tables within the Tableau data connection interface. The demonstration is done using CSVs, but the same plrinciple applies to sheets within an Excel workbook, tables within a database, or with cross database or multi-source joins as well. These type of complex joins aren't always the quickest way of getting data into a workbook, but when you're performing an ad-hoc or exploratory analysis which involves using multiple tables, this is a very efficient way of loading the data without having to write and debug lots of SQL code.
We cover:
- How to create a union.
- How to create a basic join.
- How to change the join type.
- How to change the fields used in a join.
- How to join to a secondary table (i.e. one that is not joined to the primary table).
- When you might want to use a left join vs an inner join.
- How complex joins might impact performance and why you may want to offload some of the joins to the database once your workbook goes into production.
- How the fields from a complex set of joins look once they pull into the dimensions and measures pane.

[@explorenations892]

by creating these relationships between data sets does tableau loads all of the million rows without having to filter any categories out ?