Скачать или смотреть How to Add a Nested JSONB Field with Sequelize and Postgres

Learn how to effectively add a nested JSONB field to your PostgreSQL database using Sequelize. This guide will walk you through updating `viewer_data` with a new field, complete with examples.
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How to Add a Nested JSONB Field with Sequelize and Postgres

In the world of web development, handling data structures efficiently is crucial. One common challenge developers face is working with JSONB fields in PostgreSQL, particularly when using an ORM like Sequelize. This guide addresses a specific use case: how to add a nested field (in this instance, jwt_secret) to an existing JSONB field (viewer_data) in a User model when the existing field is currently null.

The Problem

Imagine you have a User model in your application that contains a viewer_data field of type JSONB, but for some users, this field is presently null. You need to add a new field, jwt_secret, under viewer_data, ideally resulting in the following structure:

[[See Video to Reveal this Text or Code Snippet]]

What Went Wrong?

You may have tried using Sequelize's set method before updating the JSONB field, like this:

[[See Video to Reveal this Text or Code Snippet]]

However, when viewer_data is null, trying to add a nested property directly leads to errors because you cannot convert null to an object.

The Solution

The key to resolving this issue lies in properly updating the JSONB field when it is null. Here’s how you can achieve this with Sequelize:

Step-by-Step Instructions

Fetch the User Instance: Retrieve the User instance from the database using its primary key (ID).

[[See Video to Reveal this Text or Code Snippet]]

Check if viewer_data is null: Before you try to set the jwt_secret, check if viewer_data is null. If it is, you will need to initialize it.

Update the viewer_data Field: Use the set method to update viewer_data with a new object that includes the existing fields (if needed) and the new jwt_secret.

Here’s a code snippet that demonstrates this:

[[See Video to Reveal this Text or Code Snippet]]

Summary of Important Concepts

Initialize JSONB Field: Whenever viewer_data is null, you must initialize it with the necessary structure.

Maintaining Existing Data: If there’s existing data in viewer_data, spread it into the new object to avoid overwriting.

Persisting Changes: Finally, remember to call user.save() to persist the changes in the database.

Conclusion

Adding a nested field to a JSONB structure in Sequelize can indeed lead to errors if not properly managed, especially when dealing with null fields. By following the steps outlined above, you can successfully add fields to your JSONB data without running into issues. Always ensure that the structure is initialized before setting properties to avoid conversion errors.

For more advanced use cases and tips, stay tuned for further articles in our Sequelize series!