Add Migration Skill

Generates a new EF Core migration and verifies the result.

Project paths

• API project: api/Skoleoverblikket.Api/Skoleoverblikket.Api.csproj
• Migrations folder: api/Skoleoverblikket.Api/Data/Migrations/
• DbContext: AppDbContext in api/Skoleoverblikket.Api/Data/

Steps

1. Confirm migration name

If the user did not provide a name, ask for one. Migration names must be PascalCase and describe the schema change — e.g. Add_Course_Category, Remove_Staff_Slug, Add_SchemaDateRange.

2. Run the migration script

Always use the repo script — it adds the migration AND regenerates migration_script.sql atomically:

.\scripts\add-migration.ps1 -MigrationName <MigrationName>

Never call dotnet ef directly for this task. The script handles both steps and exits non-zero on failure.

3. Verify output

After the script succeeds, check that:

• Two new files exist: <timestamp>_<Name>.cs and <timestamp>_<Name>.Designer.cs
• AppDbContextModelSnapshot.cs was updated
• migration_script.sql contains the new migration ID at the bottom
• The migration Up() method contains the expected SQL operations — read it and confirm with the user if the changes look unexpected

4. Build to confirm no compile errors

dotnet build api/Skoleoverblikket.Api/Skoleoverblikket.Api.csproj --configuration Release

Rules

• Never modify an existing migration file — if a migration needs changing, add a new one
• Never run dotnet ef database update in CI or production — migrations are applied via migration_script.sql in the CI pipeline
• If the migration is empty (no Up() body), the model change was not registered — check that the entity has a corresponding IEntityTypeConfiguration<T> and is picked up by ApplyConfigurationsFromAssembly
• If dotnet ef is not installed, run: dotnet tool install --global dotnet-ef