C#•14mo ago

❔ error: Unable to create a 'DbContext' of type '' ". When adding migration to MySQL database

hi there! im just starting a webapi project and i wanted to use a mysql docker container and go code-first using the entity framework, however, im having troubles trying to add migrations, im getting the following error

Unable to create a 'DbContext' of type ''. The exception 'Method not found: 'Microsoft.EntityFrameworkCore.Storage.RelationalTypeMapping Microsoft.EntityFrameworkCore.Storage.RelationalTypeMapping.Clone(Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingInfo ByRef)'.' was thrown while attempting to create an instance. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

Unable to create a 'DbContext' of type ''. The exception 'Method not found: 'Microsoft.EntityFrameworkCore.Storage.RelationalTypeMapping Microsoft.EntityFrameworkCore.Storage.RelationalTypeMapping.Clone(Microsoft.EntityFrameworkCore.Storage.RelationalTypeMappingInfo ByRef)'.' was thrown while attempting to create an instance. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

in theory, i have my dbcontext declared

namespace Mama.Data {
    public class AppDbContext : DbContext {
        public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) { }

        public DbSet<User> Users { get; set; }
        public DbSet<Category> Categories { get; set; }
        public DbSet<Order> Orders { get; set; }
        public DbSet<OrderStatus> OrderStatuses { get; set; }
        public DbSet<OrderedProduct> OrderedProducts { get; set; }
        public DbSet<Product> Products { get; set; }
        public DbSet<Service> Services { get; set; }
        public DbSet<UserRole> UserRoles { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder) { 
            base.OnModelCreating(modelBuilder);
        }
    }
}

namespace Mama.Data {
    public class AppDbContext : DbContext {
        public AppDbContext(DbContextOptions<AppDbContext> options) : base(options) { }

        public DbSet<User> Users { get; set; }
        public DbSet<Category> Categories { get; set; }
        public DbSet<Order> Orders { get; set; }
        public DbSet<OrderStatus> OrderStatuses { get; set; }
        public DbSet<OrderedProduct> OrderedProducts { get; set; }
        public DbSet<Product> Products { get; set; }
        public DbSet<Service> Services { get; set; }
        public DbSet<UserRole> UserRoles { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder) { 
            base.OnModelCreating(modelBuilder);
        }
    }
}

and my program builds with it

var builder = WebApplication.CreateBuilder(args);
{
    var dbConn = builder.Configuration["Database:Connection"];
    var dbVersion = new MySqlServerVersion(new Version(8, 1));

    builder.Services.AddDbContext<AppDbContext>(ctx => ctx
        .UseMySql(dbConn, dbVersion)
        // TODO: Remove on prod
        .LogTo(Console.WriteLine, LogLevel.Information)
        .EnableSensitiveDataLogging()
        .EnableDetailedErrors()
    );
    ...
}

var builder = WebApplication.CreateBuilder(args);
{
    var dbConn = builder.Configuration["Database:Connection"];
    var dbVersion = new MySqlServerVersion(new Version(8, 1));

    builder.Services.AddDbContext<AppDbContext>(ctx => ctx
        .UseMySql(dbConn, dbVersion)
        // TODO: Remove on prod
        .LogTo(Console.WriteLine, LogLevel.Information)
        .EnableSensitiveDataLogging()
        .EnableDetailedErrors()
    );
    ...
}

could someone give me a hand? what am i missing?

1 Reply

Accord•14mo ago

Looks like nothing has happened here. I will mark this as stale and this post will be archived until there is new activity.

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❔ error: Unable to create a 'DbContext' of type '' ". When adding migration to MySQL database