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Created by
Jonathan Briganti, last updated on Jun 18, 2018
2 minute read
- A join allows for combining two datasets based on matching field (referred to as a "Join Clause" in Tableau Prep)
- In the examples below we are using ID as the "Join Clause"
- Depending on the type of join used your resulting dataset will vary
- For instance, an inner join will only include IDs found in both databases (so, the inside of the Venn Diagram). A left join will add all values in the first database and those of the second that have matching ID values
- If no value is found the empty cell will be represented as Null
Original Datasets
Database A |
| Database B | ||
ID | Fruit |
| ID | Vegetable |
1 | Apple |
| 3 | Lettuce |
2 | Pear |
| 4 | Carrot |
3 | Orange |
| 5 | Celery |
4 | Lemon |
| 6 | Broccoli |
The four main types of joins, and their resulting output datasets, are shown below.
Inner Join
| Left Join
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| Right Join
| Full Join
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