I am getting an error when I try to add migration in ASP.NET Core application which I connected with MySQL server of xamp

Question

This is the error I get:

Unable to create a 'DbContext' of type ''. The exception 'Method not found: 'Void CoreTypeMappingParameters..ctor(System.Type, Microsoft.EntityFrameworkCore.Storage.ValueConversion.ValueConverter, Microsoft.EntityFrameworkCore.ChangeTracking.ValueComparer, Microsoft.EntityFrameworkCore.ChangeTracking.ValueComparer, Microsoft.EntityFrameworkCore.ChangeTracking.ValueComparer, System.Func`3<Microsoft.EntityFrameworkCore.Metadata.IProperty,Microsoft.EntityFrameworkCore.Metadata.IEntityType,Microsoft.EntityFrameworkCore.ValueGeneration.ValueGenerator>)'.' was thrown while attempting to create an instance. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

Connection

"dbcs": "Server=localhost;Port=3307;Database=asp1;user=root;password=;" //this is located in json file
var connectionString = builder.Configuration.GetConnectionString("dbcs");
builder.Services.AddDbContext<StudentDbContext>(item =>
{
    item.UseMySql(connectionString,ServerVersion.AutoDetect(connectionString));
});
var app = builder.Build();

DbContext:

using Microsoft.EntityFrameworkCore;

namespace WebApplication2.Models
{
    public class StudentDbContext:DbContext
    {
        public StudentDbContext(DbContextOptions op) : base(op)
        {    
        }

        public DbSet<StudentModel> Students { get; set; }
    }
}

Model class:

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace WebApplication2.Models
{
    public class StudentModel
    {
        [Key]
        public int Id { get; set; }
        [Required(ErrorMessage = "Fill the name")]
        [Column("Student Name", TypeName="varchar(20)")]
        public string Name { get; set; }   
        public int Age { get; set; }

        public string Gender { get; set; }
    }
}

How can I solve this error? This is for .NET 8 and EF Core 8

Answer 1

I reproduced the error with following package version

Microsoft.EntityFrameworkCore(8.0.0)
Microsoft.EntityFrameworkCore.Design(8.0.0)
Microsoft.EntityFrameworkCore.Tools(8.0.0)
Pomelo.EntityFrameworkCore.MySql(7.0.0)

The issue disappeared with follwing package version:

Microsoft.EntityFrameworkCore(7.0.14)
Microsoft.EntityFrameworkCore.Design(7.0.14)
Microsoft.EntityFrameworkCore.Tools(7.0.14)
Pomelo.EntityFrameworkCore.MySql(7.0.0)

Since Pomelo.EntityFrameworkCore.Mysql lasted support version is 7.0.0, it is better keep all the efcore related packages to version 7.X.