Скачать или смотреть Resolving the Conflict resolver rejects mutation Error in AWS Amplify on Delete Operations

Learn how to solve the `Conflict resolver rejects mutation` error when attempting to delete a Note in AWS Amplify. This guide provides step-by-step solutions and best practices for working with data models in GraphQL.
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Resolving the Conflict resolver rejects mutation Error in AWS Amplify on Delete Operations

When working with AWS Amplify and GraphQL, developers may encounter various challenges, including errors that can disrupt their application's functionality. One such error is the "Conflict resolver rejects mutation." This guide will guide you through understanding why this error occurs during a delete operation and present a clear solution to resolve it.

Understanding the Problem

In a simple full-stack Amplify app, you may have defined a model for Note and NoteType. Here's a brief overview of the structure:

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

While working with this structure, a user attempts to delete a Note using a GraphQL mutation, but instead, they receive a JSON response indicating that the deletion fails with the following message:

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

This error typically indicates that there is a conflict with the mutation, potentially linked to the relationships defined in the models, particularly when dealing with foreign keys such as NoteType.

Analyzing the Cause

The error occurs because the delete operation involves a "conflict resolution." When conflicts arise in a GraphQL mutation, such as in relationships or data versions, the system needs specific information to execute the deletion properly. In your case, adding the NoteType to your Note model may have introduced additional complexity that wasn't previously accounted for in the delete operation.

Implementing the Solution

To successfully resolve the conflict and delete the Note, you need to include the _version field in your delete mutation. The _version field is crucial for tracking state and ensuring that the correct version of the data is manipulated. Here's how to modify your delete mutation:

Corrected Delete Mutation Format

Update your delete mutation as follows:

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

Then, in your variables, include the _version with the value corresponding to your Note object:

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

Additional Notes

Understanding Flagging in Conflict Resolution: After deletion, when using conflict resolution, it’s important to note that deleted items won’t be immediately removed from the database. Instead, AWS Amplify marks them with "_deleted": true and sets a "_ttl" (time to live) to expire the object, typically 30 days after deletion.

Version Management: Always keep track of your data versions when using operations that can conflict, as failing to do so can lead to similar errors.

Conclusion

Facing the "Conflict resolver rejects mutation" error while attempting to delete a Note in AWS Amplify can be frustrating, especially when the underlying issues are not immediately clear. However, by incorporating the _version field into your delete mutation, you can effectively resolve these conflicts and keep your application running smoothly.

Feel free to reach out if you have any questions or require further clarification on AWS Amplify and GraphQL operations. Happy coding!