C#C
C#•3y ago•
7 replies
sepp

✅ Layered architecture EF Core error when creating migrations

I have a Web Api project which is using .NET Core 7, my layers are DAL, Services Entities and API. I recently moved connection string to appsettings.json file (it was hardcoded in my appdbcondext class before) and created a extension method in DAL layer which sets connection string, I am using this in my startup project (API) program.cs but when I run dotnet ef migrations add testMig it gives an error 
Unable to create an object of type 'ApplicationDbContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728


It was not happening when I hard code connection string in DAL layer and add/update migrations,

ApplicationDbContext.cs (DAL)
namespace MeetingAppDemo.DAL.Context
{
    public class ApplicationDbContext : DbContext
    {
        public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
        {
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
        }
        public DbSet<User> Users { get; set; }
        public DbSet<Meeting> Meetings { get; set; }
        public DbSet<MeetingParticipant> MeetingParticipants { get; set; }
        public DbSet<MeetingDocument> MeetingDocuments { get; set; }
    }
}

DataAccessExtension.cs (DAL)
namespace MeetingAppDemo.DAL.Extensions
{
    public static class DataAccessExtensions
    {
        public static IServiceCollection SetupDbContext(this IServiceCollection services, string connectionString)
        {
            services.AddDbContext<ApplicationDbContext>(options =>
                options.UseSqlServer(connectionString));
            return services;
        }
    }
}

Program.cs (API Layer)
// Database Configuration
var dbConnectionString = builder.Configuration.GetConnectionString("Development");
builder.Services.SetupDbContext(dbConnectionString);
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