Resolving the Invalid Column Name Error in EF Core: A Developer's Guide

Описание: Discover how to solve the "Invalid column name" error in Entity Framework Core, ensuring smooth database migrations and efficient development.
---
This video is based on the question https://stackoverflow.com/q/67777895/ asked by the user 'ShanieMoonlight' ( https://stackoverflow.com/u/2826614/ ) and on the answer https://stackoverflow.com/a/67778653/ provided by the user 'ShanieMoonlight' ( https://stackoverflow.com/u/2826614/ ) 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: Invalid column name in EF Core

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.
---
Resolving the Invalid Column Name Error in EF Core: A Developer's Guide

As developers working with Entity Framework Core (EF Core), we often encounter various challenges, especially when modifying our database models. One common issue is the dreaded "Invalid column name" error, which can halt our development process. In this post, we’ll explore a specific scenario where this error arises and how to resolve it effectively.

Understanding the Problem

You might find yourself in a situation where you have modified your model classes in an IdentityDbContext. You’ve added a new property to your AppUser class, and upon running a migration, you receive an error similar to the following:

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

This error indicates that there’s a mismatch between your model classes and the database schema. Specifically, EF Core expects to find a column named ‘ABD’ based on your new code, but it hasn’t been added to the database yet due to missed migrations.

Diagnosing the Cause

In our example, the user has added a new property called ABD to the AppUser class. While migrations work smoothly when adding properties to other classes like Team, the addition of properties to AppUser can lead to problems. This discrepancy can occur due to the following reasons:

Unapplied Migrations: The database is not updated to reflect changes made in the model.

Seeding Logic: If you have data seeding logic (like a SeedUsers method) in your Startup.cs, it could lead to the application attempting to access updated tables before the migrations have been applied.

Fast Resolution

Fortunately, resolving this issue is straightforward. Here’s how you can approach it:

Comment Out Seeding Logic: If you have a seeding method like SeedUsers in your Startup.cs, one effective immediate solution is to comment it out temporarily. This prevents the application from running that part of the code during migration.

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

Run Migration Command: After commenting out the seeding logic, run the migration command again:

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

Update the Database: Next, apply your migration:

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

Re-enable Seeding Logic: Once the migration completes successfully, you can uncomment the SeedUsers method in Startup.cs to re-enable your data seeding.

Conclusion

In summary, the "Invalid column name" error in EF Core can be a roadblock, particularly when working with identity contexts and seeding logic. By ensuring that your migrations are applied correctly and being mindful of any data seeding during the migration process, you can effectively navigate this hurdle.

By taking these steps, you'll ensure a smoother development experience as you modify your Entity Framework Core models. Happy coding!