How to Remove Inverse Relationships in ASP.NET Web API 2 / MVC 5

Learn how to handle inverse relationships in ASP.NET Web API 2 and MVC 5 by simplifying the API response when fetching user data.
---
This video is based on the question https://stackoverflow.com/q/68149457/ asked by the user 'Văn Hiệp Nguyễn' ( https://stackoverflow.com/u/13410034/ ) and on the answer https://stackoverflow.com/a/68149607/ provided by the user 'Sajidur Rahman' ( https://stackoverflow.com/u/1365159/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: remove inverse relationship in ASP.NET Web API 2 / MVC 5

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding Inverse Relationships in ASP.NET Web API 2 / MVC 5

When working with data models in ASP.NET Web API and MVC, you might encounter a situation where you have inverse relationships between entities. This typically occurs when one entity has a collection of another entity, leading to circular references. For example, in the given scenario, the VISITORDRIVER and USER tables are related in such a manner. This relationship can complicate your API calls, especially when trying to return a clean, understandable JSON response.

The Problem

You need to fetch user data but want to avoid returning the entire set of associated VISITORDRIVER records in the output. This is especially important when the related entities create a circular reference, making the JSON response cumbersome and difficult to manage.

The Example JSON Structure

Here's a simplified version of how your JSON response looks when you fetch user data:

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

In this structure, the VISITORDRIVERs array is included, but in many cases, you might want to exclude or limit related entities to keep the response lightweight and focused on the main entity.

The Solution: Modifying Global.asax.cs

To resolve the issue with inverse relationships causing circular dependencies, you can adjust the settings in your Global.asax.cs file. This approach helps remove the unwanted inverse relationship data when the API serializes the output. Here's how you can do it:

Step-by-Step Instructions

Locate the Global.asax.cs file: This file contains application-level logic and configuration in your ASP.NET project.

Modify the JSON Serializer Settings: Add the following code snippet to configure the JSON serializer to avoid preserving references (which leads to circular dependencies):

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

Why This Works

Prevent Circular Dependency: By setting PreserveReferencesHandling to None, you instruct the JSON serializer to ignore the inverse navigation properties when creating the JSON output. This way, the response only includes the data relevant to the USER entity, which is typically all you need for frontend applications or API consumers.

Cleaner Output: The primary advantage is obtaining a cleaner and more focused JSON response, which reduces bandwidth and improves the clarity of the data being sent to clients.

Conclusion

Managing inverse relationships in your ASP.NET Web API 2 / MVC 5 application doesn’t have to be a complex task. By implementing the above changes to your Global.asax.cs file, you can effectively remove unwanted relational data from your API responses. This leads to cleaner, more efficient, and easier-to-understand JSON outputs, enhancing the overall performance of your application.

If you're facing similar issues with circular dependencies, implementing this solution is a recommended best practice that can save you time and effort in the long run.