Error adding models on shared project

Question

I have been able to add models on the shared project, but I currently cannot add anymore, I get the following error:

I did some research and found that the following code might help:

But instead I got this error:

-My Microsoft.EntityFrameworkCore,

Microsoft.EntityFrameworkCore.Design,

Microsoft.EntityFrameworkCore.Tools,

Microsoft.EntityFrameworkCoreServer are all the same version 7.0.13

Answer 1

Based on the error message provided by the user, it seems like there is an issue with the migration script. The error message indicates that there is a duplicate key value in the database, which means that the migration script is trying to insert a record with a primary key value that already exists in the table.

To resolve this issue, you can try deleting the migration history table and re-creating the migration script. Here are the steps to do this:

1. Open the Package Manager Console in Visual Studio.
2. Run the following command to delete the migration history table:

Drop-Table __EFMigrationsHistory

3. Delete the existing migration files in the Migrations folder.
4. Run the following command to create a new migration script:

Add-Migration InitialCreate

5. Run the following command to update the database:

Update-Database

This should create a new migration script and update the database with the latest changes. If you still encounter issues, you can try rolling back to a previous migration and then re-applying the latest migration.

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References:

• Part 4, add a model to an ASP.NET Core MVC app
• EF Core Migrations