I have a .NET Core 5 Web API using Entity Framework. The WebAPI is in a project GestionStock.API, whereas the EF with the DBContext classes in another project GestionStock.Infrastructure

I want to create the migration script by running command

Add-Migration Initiale

Unfortunately I get the error

Unable to create an object of type 'GestionStockContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?

Class DbCOntext

public class GestionStockContext : DbContext
{ 
    public GestionStockContext(DbContextOptions<GestionStockContext> options) : base(options)
    {

    }
    public DbSet<Client> Clients { get; set; }
    public DbSet<Commande> Commandes { get; set; }
    public DbSet<LignesCommandes> LignesCommandes { get; set; }
    public DbSet<Produit> Produits { get; set; }

    //Pour mettre des données par défault au début
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        base.OnConfiguring(optionsBuilder);
    }
}

Service method in Startup.cs WebApi Project

public void ConfigureServices(IServiceCollection services)
    {

        services.AddControllers();
        services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new OpenApiInfo { Title = "GestionStock.API", Version = "v1" });
        });
        services.AddDbContext<GestionStockContext>(options => 
        options.UseSqlServer(Configuration.GetConnectionString(
            "Default"),x => x.MigrationsAssembly("GestionStock.Infrastructure"))
        );
    }

CodePudding user response：

You can use the -startup-project option to specify the API project. See the documentation here: https://docs.microsoft.com/en-us/ef/core/cli/dotnet#using-the-tools

Something like:

dotnet ef migrations add MyMigrationName --startup-project GestionStock.API

CodePudding user response：

You can set the relative path to the startup and/or the DbContext project; left unset, they both will default to the current folder which only works if they're in a common project.

Options:

• --project (-p)
• --startup-project (-s)

Usage:

dotnet ef migrations add MyMigration [-p <relative path to DbContext project>, -s <relative path to startup project>]