An unhandled exception occurred while processing the request.

Question

User-605499000 posted

I got the following message below and have no idea what to do?

TypeLoadException: Method 'Create' in type 'Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerSqlTranslatingExpressionVisitorFactory' from assembly 'Microsoft.EntityFrameworkCore.SqlServer, Version=3.1.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation.

Below is my code for ApplicationDbContext:

using Bumples15.Models;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;

namespace Bumples15.Data
{
    public class ApplicationDbContext : IdentityDbContext
    {
       
        public ApplicationDbContext(DbContextOptions options) : base(options) * it underlined base(options)
        {
        }
        public DbSet<Product> Product { get; set; }
        public DbSet<Order> Order { get; set; }

    }
}

Thanks Jen

Answer 1

User711641945 posted

Hi bumples18,

TypeLoadException: Method 'Create' in type 'Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerSqlTranslatingExpressionVisitorFactory' from assembly 'Microsoft.EntityFrameworkCore.SqlServer, Version=3.1.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' does not have an implementation.

Which line makes such error?Could you share more code?

For your ApplicationDbContext,it should be like below:

public class ApplicationDbContext : IdentityDbContext
{
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
        : base(options)
    {
    }
}

Best Regards,

Rena

Answer 2

User-605499000 posted

Thank you for your reply. I put in what you gave me and still the same error.  I spent the day trying to solve the problem.  Below is a file and I wondered if that is the problem or could it be in the startup file?   Thanks for getting back to me. Jen

SQlProductRespository file

using Bumples15.Models;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;

namespace Bumples15.Service
{
public class SqlBooksRepository : IRepository<Product>
{
private readonly ApplicationDbContext _context;
private readonly ILogger _logger;

public SqlBooksRepository(ApplicationDbContext context, ILogger<SqlBooksRepository> logger)
{
_context = context;
_logger = logger;
}

public bool Add(Product item)
{
try
{
_context.Products.Add(item);
_context.SaveChanges();
return true;
}
catch (Exception ex)
{
_logger.LogError("Failed to add Book item to the database: " + ex.Message);
return false;
}
}

public bool Delete(Product Item)
{
try
{
Product product = Get(Item.ProductId);
if (product != null)
{
_context.Products.Remove(Item);
_context.SaveChanges();
return true;
}
return false;
}
catch (Exception ex)
{
_logger.LogError("Unable to delete book: " + ex.Message);
return false;
}
}

public bool Edit(Product item)
{
try
{
_context.Products.Update(item);
_context.SaveChanges();
return true;
}
catch (Exception ex)
{
_logger.LogError("Unable to save book: " + ex.Message);
}
return false;
}

public Product Get(int id)
{
if (_context.Products.Count(x => x.ProductId == id) > 0)
{
return _context.Products.FirstOrDefault(x => x.ProductId == id);
}
return null;
}

public IEnumerable<Product> GetAll()
{
return _context.Products;
}
}

public interface IRepositoryProduct
{
}
}

Answer 3

User-605499000 posted

Hi, I changed the DbContext to ApplicationDbContext on the file and that helped.  But I also had to go into the startup and change the setup for the Sqlserver. Below is what I changed

public IConfiguration Configuration { get; }

// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{



services.AddDbContext<ApplicationDbContext>(dbContextOptionBuilder => @changed
dbContextOptionBuilder.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"))); @changed

// .AddEntityFrameworkStores<ApplicationDbContext>();
services.AddScoped<RoleManager<IdentityRole>>();
services.AddScoped<IRepository<Product>, SqlBooksRepository>();
services.AddScoped<IRepository<Order>, SqlOrdersRepository>();

}

.Thank you for your help,

Jen

Answer 4

User711641945 posted

Hi bumples18,

So which line cause the error?

Besides,for your dependence inject IdentityRole,it should be like below:

services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(
        Configuration.GetConnectionString("DefaultConnection")));

services.AddIdentity<IdentityUser, IdentityRole>()
    .AddDefaultUI()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultTokenProviders();

Best Regards,

Rena

Answer 5

User-605499000 posted

Hi, your answer regarding applicationdbcontext worked. Thanks,

Jen