Use Neon branching for testing

We previously ran a DELETE query on the shoes table to remove duplicates. However the query was wrong because it didn’t specify all the criteria. Here how the query should have been written:

DELETE FROM shoes a USING shoes b
WHERE a.id > b.id
AND a.brand = b.brand
AND a.model = b.model
AND a.description = b.description
AND a.color = b.color

Since a DELETE is a sensitive operation, it is recommended to first test the query and make sure it works as expected on a new branch before trying it on the backup branch. Navigate to the Branches page and click on the New Branch button to create a new branch.

This time, we want create a test branch from Headwith the most up-to-date state of the database and specify backup as parent.

Note: if you skipped the Data recovery with branching section, you should use main as the parent branch.

Run remove duplicates query on backup branch

Let’s now navigate to the SQL Editor, select the test branch and run the query to remove duplicates.

DELETE FROM shoes a USING shoes b
WHERE a.id > b.id
AND a.brand = b.brand
AND a.model = b.model
AND a.description = b.description
AND a.color = b.color

Let’s now run a SELECT model, color FROM shoes query to verify the result.

| # |         model        | color                                          |
|---|----------------------|------------------------------------------------|
| 1 | Air Zoom Alphafly    | Scream Green/Bright Crimson/Honeydew/Black     |
| 2 | Air Zoom Alphafly    | Total Orange/Bright Crimson/Ghost Green/Black  |
| 3 | ZoomX Vaporfly       | Scream Green/Bright Crimson/Honeydew/Black     |

Yes! We managed to remove duplicates from the shoes table. We can now safely apply the same query to the parent branch.

Conclusion

Congratulations! You completed the tutorial. Here is a recap of what we covered:

• You created a Neon project, a schema and inserted data to a table
• You learned about database branching and how to use it for test and data recovery