How to add migrations for new/updated entities?

[Urganot]

Hi,
I was following your guide on how to create a new entity #34 . The issue I stumbled upon is after the first step.
After creating the new class, configuration and adding it to the ApplicationContext, I cant start the application because ef requires a migration first.

Is there a way to do that I am not aware of? The one I tried is to run the command dotnet ef migrations add test. Of course this wont work like this because it doesnt know which project to use.
The thing I dont understand is that running the command with any project specified (Im not sure which one would be the correct one. But I would guess its the infrastructure so dotnet ef migrations add Test --project src/CleanAspire.Infrastructure) will still fail with the message Your startup project 'CleanAspire.Infrastructure' doesn't reference Microsoft.EntityFrameworkCore.Design. This package is required for the Entity Framework Core Tools to work. Ensure your startup project is correct, install the package, and try again.

Is there something missing or am I doing something wrong?

[Urganot]

Simply adding the package also doesnt work because of the following:
Unable to create a 'DbContext' of type 'RuntimeType'. The exception 'Unable to resolve service for type 'Microsoft.EntityFrameworkCore.DbContextOptions`1[CleanAspire.Infrastructure.Persistence.ApplicationDbContext]' while attempting to activate 'CleanAspire.Infrastructure.Persistence.ApplicationDbContext'.' was thrown while attempting to create an instance. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

[neozhu]

Steps to Add a New Entity Class

1. Create a New Entity Class:

   • Create a new class for the entity (e.g., Product.cs) in the Entities directory of the CleanAspire.Domain project.
   • This class should typically inherit from BaseAuditableEntity and implement the IAuditTrial interface, which allows you to track audit information such as created and modified timestamps.

   public class Product : BaseAuditableEntity, IAuditTrial
   {
       public int Id { get; set; }
       public string Name { get; set; }
       public decimal Price { get; set; }
       // Other properties...
   }

2. Add DbSet<Product> to IApplicationDbContext:

   • In the IApplicationDbContext.cs file in the CleanAspire.Application project, add a DbSet<Product> property to represent the collection of Product entities in the database.

   public interface IApplicationDbContext
   {
       DbSet<Product> Products { get; }
       // Other DbSets...
   }

3. Implement DbSet<Product> in ApplicationDbContext:

   • In the ApplicationDbContext.cs file in the CleanAspire.Infrastructure project, implement the DbSet<Product> property to interact with the database.

   public class ApplicationDbContext : DbContext, IApplicationDbContext
   {
       public DbSet<Product> Products { get; set; }
       // Other DbSets...
   
       protected override void OnModelCreating(ModelBuilder modelBuilder)
       {
           base.OnModelCreating(modelBuilder);
           // Additional configurations
       }
   }

4. Define Entity Configuration for Product:

   • Define any necessary configurations for the Product entity, such as foreign keys, field lengths, etc.
   • Create a new configuration class (ProductConfiguration.cs) in the Persistence\Configurations directory under the CleanAspire.Infrastructure project. This is where you can specify constraints and configurations specific to the entity.

   public class ProductConfiguration : IEntityTypeConfiguration<Product>
   {
       public void Configure(EntityTypeBuilder<Product> builder)
       {
           builder.Property(p => p.Name).HasMaxLength(100);
           // Add other property configurations here...
       }
   }

5. Create Migration:

   • Ensure that the correct startup project is selected. It is crucial to have either CleanAspire.AppHost or CleanAspire.Api set as the startup project.

   • Open the Package Manager Console in Visual Studio and set the default project to the one that matches your database configuration in appsettings.json (e.g., Migrators.SQLite, Migrators.PostgreSQL, or Migrators.MSSQL).

     • In Package Manager Console:

     PM> Add-Migration Product
     PM> Update-Database

   • These commands will create the migration for the new Product entity and update the database accordingly.

[Urganot]

I still need to add the design package. maybe include it by default?
But even then it still fails

Your target project 'CleanAspire.Api' doesn't match your migrations assembly 'CleanAspire.Migrators.PostgreSQL'. Either change your target project or change your migrations assembly.
Change your migrations assembly by using DbContextOptionsBuilder. E.g. options.UseSqlServer(connection, b => b.MigrationsAssembly("CleanAspire.Api")). By default, the migrations assembly is the assembly containing the DbContext.
Change your target project to the migrations project by using the Package Manager Console's Default project drop-down list, or by executing "dotnet ef" from the directory containing the migrations project.

[neozhu]

Open the Package Manager Console in Visual Studio and set the default project to the one that matches your database configuration in appsettings.json (e.g., Migrators.SQLite, Migrators.PostgreSQL, or Migrators.MSSQL).

[Urganot]

Oh, I see. Now it works :) Thanks