Joining tables in Tableau - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a join in Tableau?

A join in Tableau combines rows from two or more tables based on a related column between them, allowing you to analyze combined data in one view.

beginner

Name the four main types of joins in Tableau.

Inner Join, Left Join, Right Join, and Full Outer Join.

beginner

What does an Inner Join do?

An Inner Join returns only the rows where there is a match in both tables based on the join key.

intermediate

Explain the difference between Left Join and Right Join.

A Left Join returns all rows from the left table and matching rows from the right table. A Right Join returns all rows from the right table and matching rows from the left table.

intermediate

What is a Full Outer Join in Tableau?

A Full Outer Join returns all rows from both tables. When there is no match, the result will have NULLs for missing values from either table.

Which join type returns only matching rows from both tables?

A Inner Join

B Left Join

C Right Join

D Full Outer Join

Inner Join returns only rows where the join keys match in both tables.

If you want all rows from the left table and matching rows from the right, which join do you use?

A Right Join

B Full Outer Join

C Left Join

D Inner Join

Left Join keeps all rows from the left table and adds matching rows from the right.

What happens to rows with no match in a Full Outer Join?

A They are excluded

B They appear duplicated

C They cause an error

D They appear with NULLs in missing columns

Full Outer Join includes all rows from both tables, filling missing values with NULLs.

In Tableau, where do you define the join between tables?

A In the Worksheet

B In the Data Source tab

C In the Dashboard

D In the Story

Joins are defined in the Data Source tab when connecting tables.

Which join type would you use to keep all data from both tables regardless of matches?

A Full Outer Join

B Left Join

C Right Join

D Inner Join

Full Outer Join keeps all rows from both tables, matching where possible.

Describe the four main types of joins in Tableau and when you might use each.

Think about which table's data you want to keep fully and how unmatched rows are handled.

Explain how you would join two tables in Tableau and what you should check to ensure the join works correctly.

Focus on the steps in Tableau interface and the importance of matching columns.