Скачать или смотреть How to Retrieve the Updated Record After Using ExecuteUpdate() in Entity Framework

Discover effective techniques for getting updated records after executing updates in Entity Framework. Learn how to avoid stale data issues in your integration tests!
---
This video is based on the question https://stackoverflow.com/q/76006642/ asked by the user 'Massimiliano Peluso' ( https://stackoverflow.com/u/493707/ ) and on the answer https://stackoverflow.com/a/76007113/ provided by the user 'Guru Stron' ( https://stackoverflow.com/u/2501279/ ) 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: How to get the updated record after ExecuteUpdate()?

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.
---
How to Retrieve the Updated Record After Using ExecuteUpdate() in Entity Framework

When working with the Entity Framework in C-, it's crucial to ensure that the updated records are reflected in your application, especially during testing. One common issue developers encounter is the stale data that persists after executing an update. This guide will explore how to retrieve the updated records effectively after using the ExecuteUpdateAsync() method in Entity Framework.

The Issue: Stale Data After Execution

Imagine you are running an integration test where you update a user’s following count. You execute the following code:

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

After executing the update, you check the database and confirm that the value has been updated correctly. However, when you attempt to retrieve the updated value using:

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

You find that the updatedValue remains zero! What’s going wrong here? The problem lies in how the Entity Framework context is managing change tracking and stale data.

Understanding the Problem

When you perform an update using ExecuteUpdateAsync(), this method directly modifies the data in the database without utilizing the change tracker mechanism. If you're maintaining the same context instance for fetching data after the update, you may encounter stale data because the context has not been notified of the changes made outside of its tracking capabilities.

Key Points to Consider:

Change Tracking: The context uses an internal mechanism to keep track of changes in your entities. If you fetch objects while the context is not aware of updates made directly to the database, stale data will be used.

Context Instance: Using the same instance of your database context before and after executing an update can lead to retrieving outdated states of your entities.

Solutions to Retrieve the Updated Records

To resolve this issue, you have several options:

1. Recreate the DB Context

One way to ensure that you get the latest data is by creating a new instance of your database context. This allows you to bypass the change tracking issues.

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

2. Clear the Change Tracker

If you want to reuse the existing context, an alternative is to clear the change tracker. This effectively resets the context's knowledge of entity states.

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

3. Explicitly Reload the Entity

You can also opt to manually reload the entity by using the Reload() method. This re-fetches the current entity state from the database.

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

4. Use AsNoTracking

Another approach is to execute the query without tracking. Using AsNoTracking() allows you to retrieve fresh, untracked data from the database, ensuring it reflects the most recent updates.

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

Conclusion

Handling data updates in Entity Framework requires careful attention to how the context manages state. By understanding how to retrieve updated values correctly after executing updates, you can avoid issues with stale data and improve the reliability of your integration tests. The methods outlined above provide versatile solutions to ensure that your application reflects the most current data after update operations.

Explore these techniques and see which one best fits your workflow. Remember, leveraging the power of Entity Framework efficiently can significantly enhance your application's performance and reliability.