System.TypeLoadException: Method 'Create' in type 'MySql.Data.EntityFrameworkCore.Query.Internal.MySQLSqlTranslatingExpressionVisitorFactory'

Question

I'm trying to add a new user to the database with the following code:

public async void SeedUsers(){
    int count=0;
    if(count>0){
        return;
    }
    else{
        string email="[email protected]";
        _context.Add(new User{LoginEmail=email});  
        await _context.SaveChangesAsync();  
    }
}

But it keeps giving me the following error:

System.TypeLoadException: Method 'Create' in type 'MySql.Data.EntityFrameworkCore.Query.Internal.MySQLSqlTranslatingExpressionVisitorFactory' from >assembly 'MySql.Data.EntityFrameworkCore, Version=8.0.22.0, Culture=neutral, >PublicKeyToken=c5687fc88969c44d' does not have an implementation. at MySql.Data.EntityFrameworkCore.Extensions.MySQLServiceCollectionExtensions.AddEntityFrameworkMySQL(IServ>iceCollection services) at MySql.Data.EntityFrameworkCore.Infrastructure.Internal.MySQLOptionsExtension.ApplyServices(IServiceColle>ction services) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.ApplyServices(IDbContextOptions >options, ServiceCollection services) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.<c__DisplayClass4_0.g__BuildServiceProvider|3() at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.<>c__DisplayClass4_0.b__2(Int64 k) at System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd(TKey key, Func2 valueFactory) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.GetOrAdd(IDbContextOptions options, >Boolean providerRequired) at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider() at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies() at Microsoft.EntityFrameworkCore.DbContext.EntryWithoutDetectChanges[TEntity](TEntity entity) at Microsoft.EntityFrameworkCore.DbContext.SetEntityState[TEntity](TEntity entity, EntityState >entityState) at Microsoft.EntityFrameworkCore.DbContext.Add[TEntity](TEntity entity) at contatinApi.Data.SeedData.SeedUsers() in D:\dev\contatinapi\Data\SeedData.cs:line 24 at System.Threading.Tasks.Task.<>c.b__139_1(Object state) at System.Threading.QueueUserWorkItemCallback.<>c.<.cctor>b__6_0(QueueUserWorkItemCallback quwi) at System.Threading.ExecutionContext.RunForThreadPoolUnsafe[TState](ExecutionContext >executionContext, Action`1 callback, TState& state) at System.Threading.QueueUserWorkItemCallback.Execute() at System.Threading.ThreadPoolWorkQueue.Dispatch() at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()

The User class:

public class User
    {
        public int Id{get;set;}
        public string LoginEmail{get;set;}
        public string UserName{get;set;}
        public DateTime CreatedAt{get;set;}
        public List<Contact> Contacts {get;set;}
        public List<ContactList> ContactLists{get;set;}
    }

Both the EF Core and MySQL packages are updated. Also, i tried using stored procedures and it gave the same results.

The content of Ex was:

The value of Ex was {System.TypeLoadException: Method 'Create' in type 'MySql.Data.EntityFrameworkCore.Query.Internal.MySQLSqlTranslatingExpressionVisitorFactory' from assembly 'MySql.Data.EntityFrameworkCore, Version=8.0.22.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d' does not have an implementation. at MySql.Data.EntityFrameworkCore.Extensions.MySQLServiceCollectionExtensions.AddEntityFrameworkMySQL(IServiceCollection services) at MySql.Data.EntityFrameworkCore.Infrastructure.Internal.MySQLOptionsExtension.ApplyServices(IServiceCollection services) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.ApplyServices(IDbContextOptions options, ServiceCollection services) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.<>c__DisplayClass4_0.g__BuildServiceProvider|3() at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.<>c__DisplayClass4_0.b__2(Int64 k) at System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd(TKey key, Func2 valueFactory) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.GetOrAdd(IDbContextOptions options, Boolean providerRequired) at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider() at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies() at Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Internal.IDbContextDependencies.get_StateManager() at Microsoft.EntityFrameworkCore.Internal.InternalDbSet1.EntryWithoutDetectChanges(TEntity entity) at Microsoft.EntityFrameworkCore.Internal.InternalDbSet1.Add(TEntity entity) at contatinApi.Data.SeedData.SeedUsers() in D:\dev\ContatinApi\Data\SeedData.cs:line 40}

Answer 1

If you're using Microsoft.EntityFrameworkCore 5.0 downgrade it to Microsoft.EntityFrameworkCore 3.1.10 MySQL EF 8.0.22 is currently not compatiable with Microsoft.EntityFrameworkCore 5.0

I have a working Code until I upgraded to Microsoft.EntityFrameworkCore 5.0 then I got same error, Downgraded and it worked!

Hoping to post a Bug report on MySQL Bug Forum

Answer 2

I have resolved this issue following this:-

1. upgrade Microsoft.EntityFrameworkCore to version 5.0.1

2. upgrade Pomelo.EntityFrameworkCore.MySql to version 5.0.0-alpha.2

3. add the code blocks into ConfigureServices method of Startup.cs file

   var connectionString = _configuration.GetConnectionString("userDB"); services.AddDbContext(options =>
   options.UseMySql(connectionString,new MySqlServerVersion(new Version(10, 1, 40)), mySqlOptions => mySqlOptions .CharSetBehavior(CharSetBehavior.NeverAppend)));

To get mysql server version run the query to any of mysql server editor like MySql Workbench or HeidiSQL

SELECT VERSION()