ef database updata is unable to find migration - entity-framework-core

Question

I am trying to perform a consolidation or merge of migrations on one of many DBContexts.
We have a .NET 6 solution which utilizes several databases. All db contexts have been defined in a single project, in separate folders. I.e.
Solution\
- Business_Logic_Project_1\
- Business_Logic_Project_2\
- Business_Logic_Project_3\
- Database_Project\
- Context1\
- Migrations\
- Models\
- Context1.cs
- Context2\
- Migrations\
- Models\
- Context2.cs
- Context3\
- Migrations\
- Models\
- Context3.cs
- Database_Project.csproj
- Startup_Project
- Startup_Project.csproj
- Solution.sln
I do the following:
I open a command prompt and go to the root of the solution.
I then delete all migrations in the Database_Project\Context2\Migrations.
I then execute this command:
dotnet ef migrations add <<MIGRATION_NAME>> --context Context2 --project Database_Project --startup-project Startup_Project --output-dir Context2\Migrations
I empty the __EFMigrationsHistory table in the database.
Finally, I run this command to finish the consolidation:
dotnet ef database update <<MIGRATION_NAME>> --context Context2 --project Database_Project --startup-project Startup_Project
This fails with the error message: The migration '<<MIGRATION_NAME>>' was not found.
So, I think this is because the migrations are placed under the context folders, and the database update command do not look that deep. There doesn't appear to be a way of telling the command where to look for migrations though, so what to do?

Answer 1

Hard to pinpoint the exact reason but, while providing the migration name in update command, did you include the .cs extension? If so, please try without that.
Other possibilities include
some typo in the command
missing migration designer files

Answer 2

Well, I figured it out, but I forgot about this question, so I can't remember the issue and how I solved it.
However, I found that these steps works:
Step 1: Delete all *.cs files under the Migrations folder. Except the *ModelSnapshot.cs.
Step 2: Copy all records from the __EFMigrationHistory to the __EFMigrationHistoryBackup:
INSERT INTO dbo.[__EFMigrationHistoryBackup] (MigrationId, ProductVersion)
SELECT MigrationId, ProductVersion FROM dbo.[__EFMigrationsHistory]
Step 3: Empty the __EFMigrationHistory table:
DELETE FROM dbo.[__EFMigrationHistory]
Step 4: Create a new migration like: dotnet ef migrations add Migration_Merge_2022Q4.
Both the Up() and Down() methods of the migration should be empty. If not, comment out all code inside the two methods.
Step 5: Update the database like: dotnet ef database update. This should add a new record in the __EFMigrationHistory table, but since Up() and Down() is empty, no changes is made to the database.
Step 6: Uncomment the Up() and Down() methods.
Step 7: Check the changes into Git.