> ## Documentation Index > Fetch the complete documentation index at: https://mintlify.com/AlexanderAsprilla98/Tournament-Management-App/llms.txt > Use this file to discover all available pages before exploring further. # Entity Framework Migrations > Database schema management with EF Core migrations ## Overview Entity Framework Core migrations provide a way to incrementally update the database schema to keep it in sync with the application's data model while preserving existing data. The Tournament Management App uses migrations for two separate contexts: * **DataContext**: Tournament domain entities * **IdentityDataContext**: ASP.NET Core Identity tables *** ## Migration Workflow The standard workflow for working with migrations involves these steps: Install the `dotnet-ef` global tool: ```bash theme={null} dotnet tool install --global dotnet-ef --version 8 ``` Modify entity classes in the `Torneo.App.Dominio` project or update the `DataContext`/`IdentityDataContext` configuration. Generate a new migration file that captures the model changes: ```bash theme={null} # For DataContext dotnet ef migrations add MigrationName \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext # For IdentityDataContext dotnet ef migrations add MigrationName \ --project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Frontend.Areas.Identity.Data.IdentityDataContext ``` Examine the generated migration file in the `Migrations` folder to ensure it correctly represents your changes. Update the database schema: ```bash theme={null} # For DataContext dotnet ef database update \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext # For IdentityDataContext dotnet ef database update \ --project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Frontend.Areas.Identity.Data.IdentityDataContext ``` *** ## Docker Build Migrations The application's Dockerfile includes automated migration creation and execution during the build process. This ensures a fresh database schema is always available in the container. ### Build Process ```dockerfile Dockerfile (lines 19-35) theme={null} # Create and apply DataContext migrations dotnet ef migrations add InitialCreate \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext \ --no-build --configuration Release dotnet ef database update \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext # Create and apply IdentityDataContext migrations dotnet ef migrations add CreateIdentitySchema \ --project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Frontend.Areas.Identity.Data.IdentityDataContext \ --no-build --configuration Release dotnet ef database update \ --project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Frontend.Areas.Identity.Data.IdentityDataContext ``` The Docker build process creates two migrations: * `InitialCreate` for the DataContext (tournament data) * `CreateIdentitySchema` for the IdentityDataContext (user authentication) *** ## Migration Commands Reference ### Creating Migrations #### DataContext Migration ```bash Create DataContext Migration theme={null} dotnet ef migrations add MigrationName \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` #### IdentityDataContext Migration ```bash Create IdentityDataContext Migration theme={null} dotnet ef migrations add MigrationName \ --project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Frontend.Areas.Identity.Data.IdentityDataContext ``` ### Applying Migrations #### Update to Latest Migration ```bash Update DataContext theme={null} dotnet ef database update \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` ```bash Update IdentityDataContext theme={null} dotnet ef database update \ --project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Frontend.Areas.Identity.Data.IdentityDataContext ``` #### Update to Specific Migration ```bash Target Specific Migration theme={null} dotnet ef database update MigrationName \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` ### Listing Migrations ```bash List DataContext Migrations theme={null} dotnet ef migrations list \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` ### Removing Migrations Only remove a migration if it hasn't been applied to any database yet. If the migration has been applied, you must roll it back first. ```bash Remove Last Migration theme={null} dotnet ef migrations remove \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` ### Generating SQL Scripts Generate SQL scripts without applying them to the database: ```bash Generate SQL Script theme={null} dotnet ef migrations script \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext \ --output migration.sql ``` *** ## Rollback Procedures To rollback the database to a previous migration: View all migrations to identify the target migration: ```bash theme={null} dotnet ef migrations list \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` Rollback to a specific migration: ```bash theme={null} dotnet ef database update PreviousMigrationName \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` After rolling back, remove the migration files: ```bash theme={null} dotnet ef migrations remove \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` ### Rollback to Empty Database To completely reset the database: ```bash Rollback All Migrations theme={null} dotnet ef database update 0 \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext ``` Using `dotnet ef database update 0` will remove all tables from the database. This operation is destructive and will result in data loss. *** ## Common Issues and Solutions ### Issue: "No executable found matching command dotnet-ef" **Solution**: Install the EF Core tools globally: ```bash theme={null} dotnet tool install --global dotnet-ef --version 8 ``` Verify installation: ```bash theme={null} dotnet ef --version ``` ### Issue: "Build failed" **Solution**: Build the solution before creating migrations: ```bash theme={null} dotnet build Torneo.App.sln -c Release ``` Then add the `--no-build` flag to the migration command: ```bash theme={null} dotnet ef migrations add MigrationName \ --project Torneo.App.Persistencia/Torneo.App.Persistencia.csproj \ --startup-project Torneo.App.Frontend/Torneo.App.Frontend.csproj \ --context Torneo.App.Persistencia.DataContext \ --no-build --configuration Release ``` ### Issue: "Your startup project doesn't reference Microsoft.EntityFrameworkCore.Design" **Solution**: Ensure the startup project (`Torneo.App.Frontend`) has the following package reference: ```xml Torneo.App.Frontend.csproj theme={null} runtime; build; native; contentfiles; analyzers; buildtransitive all ``` ### Issue: "Unable to create an object of type 'DataContext'" **Solution**: Ensure the `DATABASE_CONNECTION_STRING` environment variable is set: ```bash theme={null} export DATABASE_CONNECTION_STRING="Data Source=/app/Torneo.db" ``` Or update the `OnConfiguring` method in `DataContext.cs` to use a hardcoded connection string for development. ### Issue: Foreign Key Constraint Violations **Solution**: The application uses `DeleteBehavior.Restrict` for all relationships. When deleting entities, you must: 1. First delete or update all dependent entities 2. Then delete the parent entity Example: ```csharp Delete Team with Dependencies theme={null} // First remove players from the team foreach (var jugador in equipo.Jugadores) { context.Jugadores.Remove(jugador); } // Then remove the team context.Equipos.Remove(equipo); context.SaveChanges(); ``` ### Issue: Migration Conflicts in Docker Build **Solution**: If migrations already exist, the Docker build will fail. Either: 1. Remove existing migrations before building: ```bash theme={null} rm -rf Torneo.App.Persistencia/Migrations rm -rf Torneo.App.Frontend/Migrations ``` 2. Modify the Dockerfile to check for existing migrations before creating new ones *** ## Migration Files Structure Migration files are generated in the following locations: * **DataContext migrations**: `Torneo.App.Persistencia/Migrations/` * **IdentityDataContext migrations**: `Torneo.App.Frontend/Migrations/` Each migration consists of three files: 1. `[Timestamp]_[MigrationName].cs` - Contains `Up()` and `Down()` methods 2. `[Timestamp]_[MigrationName].Designer.cs` - Metadata for the migration 3. `[ContextName]ModelSnapshot.cs` - Current state of the entire model ### Example Migration Structure ```csharp Migration Up Method theme={null} public partial class InitialCreate : Migration { protected override void Up(MigrationBuilder migrationBuilder) { migrationBuilder.CreateTable( name: "Municipios", columns: table => new { Id = table.Column(nullable: false) .Annotation("Sqlite:Autoincrement", true), Nombre = table.Column(maxLength: 50, nullable: false) }, constraints: table => { table.PrimaryKey("PK_Municipios", x => x.Id); }); } protected override void Down(MigrationBuilder migrationBuilder) { migrationBuilder.DropTable(name: "Municipios"); } } ``` *** ## Environment Variables The following environment variables affect migration behavior: SQLite connection string. Override to use a different database location or SQL Server. SQL Server SA password. Only required if using SQL Server instead of SQLite. *** ## Best Practices 1. **Always review migrations** before applying them to production databases 2. **Test migrations** on a development database first 3. **Back up your database** before applying migrations in production 4. **Use descriptive migration names** that indicate what changed (e.g., `AddPhoneNumberToDirector`, `CreatePartidoTable`) 5. **Never modify applied migrations** - create a new migration instead 6. **Keep migrations small** - one logical change per migration 7. **Generate SQL scripts** for production deployments instead of running migrations directly *** ## Related Documentation Learn about DataContext and IdentityDataContext Explore the domain model entities