I am developing a .NET CORE MVC 2.1 Web Application with a DbContext declared in a DLL (EF Core 2.1).
I would like to configure the context using IServiceCollection.AddContext<GladContext> but if I do not ALSO configures it DbContext.OnConfiguring(DbContextOptionsBuilder optionsBuilder) I am told that No database provider has been configured for this DbContext despite having a constructor taking a DbContextOptions<GladContext>
public GladContext(DbContextOptions<GladContext> options, IGladConnectionStringProvider connectionStringProvider) : base(options)
{
_connectionStringProvider = connectionStringProvider;
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
GladOptionsBuilderHelper.ConfigureDefaultOptionsBuilder(optionsBuilder, _connectionStringProvider.ConnectionString);
base.OnConfiguring(optionsBuilder);
}
The IGladConnectionStringProvider is my current workaround and that is acceptable if it wasn't because I now need to configure both DbContextOptionsBuilder and DbContextOptionsBuilder<GladContext>
public static class GladOptionsBuilderHelper
{
public const string GladMigrationsHistory = "__GladMigrationsHistory";
public static DbContextOptionsBuilder<GladContext> CreateDefaultTypedOptionsBuilder(string connectionString)
{
var optionsBuilder = new DbContextOptionsBuilder<GladContext>();
optionsBuilder
.UseSqlServer(connectionString, options =>
{
options.EnableRetryOnFailure();
options.MigrationsHistoryTable(GladMigrationsHistory, EntityBase.SchemaName);
})
.ConfigureWarnings(warnings => warnings.Throw(RelationalEventId.QueryClientEvaluationWarning));
return optionsBuilder;
}
public static void ConfigureDefaultOptionsBuilder(DbContextOptionsBuilder optionsBuilder, string connectionString)
{
optionsBuilder
.UseSqlServer(connectionString, options =>
{
options.EnableRetryOnFailure();
options.MigrationsHistoryTable(GladMigrationsHistory, EntityBase.SchemaName);
})
.ConfigureWarnings(warnings => warnings.Throw(RelationalEventId.QueryClientEvaluationWarning));
}
}
The DbContextOptionsBuilder<GladContext> is used in IDesignTimeDbContextFactory<GladContext>
Can you can tell me how to use AddContext to configure GladContext or how to construct a DbContextOptionsBuilder from a DbContextOptionsBuilder<GladContext> or the other way around?
The configuration part of it is an override of the IServiceCollection.AddDbContext().
So, when you call AddDbContext, just add your options into the parentheses like so:
var connectionString = "CONNECTION-STRING-HERE";
services.AddDbContext<MyContext>(o => o
.UseSqlServer(connectionString)
.UseQueryTrackingBehavior(true)
.EnableSensitiveDataLogging(true));
public class MyContext : DbContext
{
public DbSet<Blog> Blogs { get; set; }
public MyContext(DbContextOptions<MyContext> options) : base(options)
{
}
}
Related
Background - I am using Entity framework code version 2.1.4-rtm-31024
check out the CODE LISTING 1 - the problem (according to Ms Build Engine 15.9) is that GetAllMakes calls .ToList, but no 'ToList' method exists for a DbSet of VehicleMake. (check out Code Listing 2) to see the implementation of _vehicleContext.VehicleMakes
Why do I get a compile error? this makes no sense to me since I can call VehicleMakes.ToList() elsewhere in the code (no compiler error) no problem at all - see listing 3 for an example.
CODE LISTING 1
using System.Collections.Generic;
namespace CarPriceComparison.Models
{
public class VehicleRepository : IVehicleRepository
{
private VehicleContext _vehicleContext;
public VehicleRepository(VehicleContext dbContext_)
{
_vehicleContext = dbContext_;
}
public IEnumerable<VehicleMake> GetAllMakes()
{
return _vehicleContext.VehicleMakes.ToList();
}
}
}
CODE LISTING 2
namespace CarPriceComparison.Models
{
public class VehicleContext : DbContext
{
private IConfigurationRoot _config;
public VehicleContext(IConfigurationRoot config_, DbContextOptions
options_) : base(options_)
{
_config = config_;
}
public DbSet<VehicleMake> VehicleMakes {get; set;}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
base.OnConfiguring(optionsBuilder);
optionsBuilder.UseSqlServer(_config["ConnectionStrings:VehicleContextConnection"]);
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<VehicleModel>()
.HasOne(p => p.Make)
.WithMany(b => b.Models)
.HasForeignKey(p => p.VehicleMakeForeignKey)
.IsRequired()
.OnDelete(DeleteBehavior.Cascade);
}
}
}
CODE LISTING 3
private VehicleContext _vehicleContext;
private IMailService _mailService;
private IConfigurationRoot _config;
public HomeController(IMailService mailService_, IConfigurationRoot
config_, VehicleContext vehicleContext_)
{
_vehicleContext = vehicleContext_;
_mailService = mailService_;
_config = config_;
}
public IActionResult Index()
{
var vehicleData = _vehicleContext.VehicleMakes.ToList();
return View();
}
I think you missing an using statement.
using System.Linq;
Hi I have created my UnitOfWork as generic and at runtime it should create new instance of DB context with DBContextOption Builder on the basis of TContext passing I have registered Mention DB Context in autofac but how to resolve this at DB Context Constructor Level
DB Context 1 Implemetation
public class DBContext1 : DbContext
{
public DBContext1(DbContextOptions<DBContext1> options1) : base(options1)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
}
}
DB Context 2 Implemetation
public class DBContext2 : DbContext
{
public DBContext2(DbContextOptions<DBContext2> options2) : base(options2)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
}
}
IUnitOfWork interface Implemetation
public interface IUnitOfWork<TContext> where TContext : DbContext, IDisposable
{
}
UnitOfWork class Implemetation
public class UnitOfWork<TContext> : IDisposable, IUnitOfWork<TContext> where TContext : DbContext, new()
{
private DbContext _context;
public UnitOfWork()
{
_context = new TContext();
}
}
StartUp Class Implemetation
public class Startup
{
protected IConfiguration _configuration { get; set; }
public Startup(IConfiguration configuration)
{
_configuration = configuration;
}
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddMvc();
services.AddEntityFrameworkSqlServer()
.AddDbContext<DBContext1>(options =>
options.UseSqlServer(_configuration.GetConnectionString("DBContext1")))
.AddDbContext<DBContext2>(options =>
options.UseSqlServer(_configuration.GetConnectionString("DBContext2")));
/* Autofac DI Configuration with registering DBContext/DataModule/ServiceModule to it */
var containerBuilder = new ContainerBuilder();
containerBuilder.RegisterInstance(_configuration).AsImplementedInterfaces().ExternallyOwned();
var autoFacOptions1 = new DbContextOptionsBuilder<DBContext1>().UseSqlServer(_configuration.GetConnectionString("DBContext1")).Options;
var autoFacOptions2 = new DbContextOptionsBuilder<DBContext2>().UseSqlServer(_configuration.GetConnectionString("DBContext2")).Options;
containerBuilder.Register(c => new DBContext1(autoFacOptions1)).As<DbContext>();
containerBuilder.Register(c => new DBContext2(autoFacOptions2)).As<DbContext>();
containerBuilder.RegisterModule<DataModule>();
containerBuilder.RegisterModule<ServiceModule>();
containerBuilder.Register<String>(c => Guid.NewGuid().ToString())
.Named<String>("correlationId")
.InstancePerLifetimeScope();
containerBuilder.Populate(services);
var container = containerBuilder.Build();
return new AutofacServiceProvider(container);
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Account}/{action=Login}/{id?}");
});
app.Run(async (context) =>
{
await context.Response.WriteAsync("Hello World!");
});
}
}
I am able to achieve multiple DBContext Call as required but I have to create Default constructor & connection string in DB context like mention below
DB Context 1 Implemetation
public class DBContext1 : DbContext
{
public DBContext1()
{
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer(#"Data Source=Server;Database=DB;User Id=UserID;Password=Password;Integrated Security=False;MultipleActiveResultSets=true;");
}
public DBContext1(DbContextOptions<DBContext1> options1) : base(options1)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
}
}
DB Context 2 Implemetation
public class DBContext2 : DbContext
{
public DBContext2()
{
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
optionsBuilder.UseSqlServer(#"Data Source=Server;Database=DB;User Id=UserID;Password=Password;Integrated Security=False;MultipleActiveResultSets=true;");
}
public DBContext2(DbContextOptions<DBContext2> options2) : base(options2)
{
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
}
}
Please help me to call parameterised constructor of DBContext1 & DBContext2 using autofac dependency resolver
Well, if you're using autofac to resolve dependencies then why are you trying to do its job for it? :) That's the main problem with your code.
First of all, you don't need to register IConfiguration explicitly. It is already registered in the IServiceCollection that's passed to ConfigureServices() method and will be automatically picked up by autofac during containerBuilder.Populate(services) call. You can just remove this registration and nothing will change.
Further, you're registering both your DbContexts twice - in the service collection and in the autofac container builder. This is not necessary as the latter will effectively replace the former. Also, it creates confusion about what is registered where and how this whole this is going to work. It's better to pick one method of registration and stick with it.
Next problem: how are you going to unit test your unit of work? It has hard dependency on DbContext whose lifecycle you cannot control in tests. This is exactly what you need autofac for: manage component's dependencies for you allowing you to concentrate on the component's purpose and not on the secondary stuff.
Next confusion point is here:
containerBuilder.Register(c => new DBContext1(autoFacOptions1)).As<DbContext>();
containerBuilder.Register(c => new DBContext2(autoFacOptions2)).As<DbContext>();
By doing this you are effectively replacing first db context registration with the second. From this point there is no way to inject DBContext1 anywhere in your application. EDITED: You still can inject collection of DbContext derivative implementations and find DBContext1 among them... but that would look very weird.
All in all, this can be done in much more clean and straightforward way.
Startup
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddMvc();
var builder = new ContainerBuilder();
builder.Register(c => c.CreateDbContextOptionsFor<DBContext1>("DBContext1")).As<DbContextOptions<DBContext1>>().SingleInstance();
builder.Register(c => c.CreateDbContextOptionsFor<DBContext2>("DBContext2")).As<DbContextOptions<DBContext2>>().SingleInstance();
builder.RegisterType<DBContext1>().AsSelf().InstancePerLifetimeScope();
builder.RegisterType<DBContext2>().AsSelf().InstancePerLifetimeScope();
builder.RegisterType<SomeComponent>().As<ISomeComponent>().InstancePerLifetimeScope();
builder.RegisterGeneric(typeof(UnitOfWork<>)).As(typeof(IUnitOfWork<>)).InstancePerLifetimeScope();
builder.Populate(services);
var container = builder.Build();
return new AutofacServiceProvider(container);
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
....
}
}
CreateDbContextOptionsFor helper implementation. It is introduced in order to make Startup code concise and more readable. It can probably be improved even further by making use of autofac's parameterized factory instead of new DbContextOptionsBuilder<TContext>(), but I'm not sure if there's a point in it in this case.
public static class DBExtentions
{
public static DbContextOptions<TContext> CreateDbContextOptionsFor<TContext>(this IComponentContext ctx,
string connectionName) where TContext : DbContext
{
var connectionString = ctx.Resolve<IConfiguration>().GetConnectionString(connectionName);
return new DbContextOptionsBuilder<TContext>().UseSqlServer(connectionString).Options;
}
}
UnitOfWork
public class UnitOfWork<TContext> : IUnitOfWork<TContext> where TContext : DbContext
{
private TContext _context;
public UnitOfWork(TContext context)
{
_context = context;
}
}
Injecting and using unit of work
public class SomeComponent : ISomeComponent
{
private readonly IUnitOfWork<DBContext1> _uow;
public SomeComponent(IUnitOfWork<DBContext1> uow)
{
_uow = uow;
}
public void DoSomething()
{
_uow.DoWhatever();
}
....
I have 2 project, Data and Data.test, I use ef core and .net core for both of them, for Data project I have ExpenseDb like this:
public class ExpenseDb: DbContext
{
private IConfigurationRoot _config;
public ExpenseDb(DbContextOptions<ExpenseDb> options, IConfigurationRoot config) : base(options)
{
_config = config;
}
public DbSet<Account> Accounts { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
base.OnConfiguring(optionsBuilder);
optionsBuilder.UseSqlServer(_config["Data:ConnectionString"]);
}
}
And I have a repository for Account like this:
private ExpenseDb _db;
public AccountRepository(ExpenseDb db)
{
_db = db;
}
public IEnumerable<Account> All(Guid userId)
{
return (_db.Accounts.AsNoTracking().Where(a => a.UserId == userId).ToList());
}
I use ms IOC for injectiong dependencies like this :
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json");
_config = builder.Build();
}
IConfigurationRoot _config;
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton(_config);
services.AddDbContext<ExpenseDb>(ServiceLifetime.Scoped);
}
These all are in my Data project, and for Data.Test I would like to test All method, I realized I must Mock my ExpenseDb so I got Moq from Nuget Package and now I have test class like this :
[TestClass]
public class AccountRepositoryTest
{
private readonly Mock<ExpenseDb> _dbMock = new Mock<ExpenseDb>();
private readonly AccountRepository _repo;
public AccountRepositoryTest()
{
_repo = new AccountRepository(_dbMock.Object);
}
[TestMethod]
public void AllForInvalidUser()
{
var fakeaccount = new Account() { Name="cat2",OpenDate=DateTime.Now,StartBalance=100};
Mock < DbSet < Account >> acMock = DbSetMock.Create(fakeaccount);
var results = _repo.All(Guid.Parse("cf15c6c9-f688-47ee-892e-297e530be053"));
Assert.IsNotNull(results);
}
}
Obviously my test is failed, because I must pass config and options to my ExpenseDb somehow, but I don't know How?!
I searched and I found out all answer are saying "You must have an inteface for your service" but i don't want to create an unnecessary interface.
Since DbContextOptions and config are not being used in the actual test code. You could create a constructor in your db context marked as protected to allow the instantiation of the ExpenseDb object without any params.
Using ASP.NET Core MVC and Entity Framework 6, I want to seed my code-first database with data from a CSV file that I have placed in wwwroot\data
I am trying to access the WebRootPath value in the class that performs the seed but cannot get it to work. I understand the solution is based on Dependency Injection though being very new to ASP.NET Core and Dependency Injection I haven't got this to work.
Startup.cs - Standard code, DbContext setup found via another SO question.
public class Startup
{
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddEnvironmentVariables();
Configuration = builder.Build();
}
public IConfigurationRoot Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
// Add DbContext
services.AddScoped(p =>
{
var connectionString = Configuration["Data:ProjectDbContext:ConnectionString"];
return new ProjectDbContext(connectionString);
});
// Add framework services.
services.AddMvc();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseBrowserLink();
}
else
{
app.UseExceptionHandler("/Home/Error");
}
app.UseStaticFiles();
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});
}
}
ProjectDbContext.cs
[DbConfigurationType(typeof(DbConfig))]
public class ProjectDbContext : DbContext
{
static ProjectDbContext ()
{
Database.SetInitializer(new ProjectInitializer());
}
public ProjectDbContext (string connectionName) : base(connectionName)
{
}
public DbSet<SomeEntity> SomeEntity{ get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
base.OnModelCreating(modelBuilder);
}
}
ProjectInitializer.cs
public class ProjectInitializer : DropCreateDatabaseAlways<ProjectDbContext>
{
private readonly IHostingEnvironment _appEnvironment;
public ProjectInitializer(IHostingEnvironment appEnvironment)
{
_appEnvironment = appEnvironment;
}
public override void InitializeDatabase(ProjectDbContext context)
{
base.InitializeDatabase(context);
}
protected override void Seed(ProjectDbContext db)
{
string dataPath = Path.Combine(_appEnvironment.WebRootPath, "data");
string contracts = Path.Combine(dataPath, "Data.csv");
// Parse file, create objects
db.SaveChanges();
}
}
I have changed my classes as follows, it works though I'm not sure it is entirely correct:
Startup.cs
public Startup(IHostingEnvironment env)
{
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddEnvironmentVariables();
Configuration = builder.Build();
HostingEnvironment = env;
}
public IHostingEnvironment HostingEnvironment { get; }
public IConfigurationRoot Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
// Add DbContext
services.AddScoped(p =>
{
var connectionString = Configuration["Data:ProjectDbContext:ConnectionString"];
return new ProjectDbContext(connectionString, HostingEnvironment);
});
// Add framework services.
services.AddMvc();
}
ProjectDbContext.cs
[DbConfigurationType(typeof(DbConfig))]
public class ProjectDbContext : DbContext
{
public ProjectDbContext(string connectionName, IHostingEnvironment appEnvironment) : base(connectionName)
{
Database.SetInitializer(new ProjectInitializer(appEnvironment));
}
public DbSet<SomeEntity> SomeEntity { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
base.OnModelCreating(modelBuilder);
}
}
ProjectInitializer.cs
private readonly IHostingEnvironment _appEnvironment;
public ProjectInitializer(IHostingEnvironment appEnvironment)
{
_appEnvironment = appEnvironment;
}
public override void InitializeDatabase(ProjectDbContext context)
{
base.InitializeDatabase(context);
}
protected override void Seed(ProjectDbContext db)
{
string dataPath = Path.Combine(_appEnvironment.WebRootPath, "data");
string contracts = Path.Combine(dataPath, "Data.csv");
// Parse file, create objects
db.SaveChanges();
}
Trying to load all the configurations dynamically on OnModelCreating for Entity framework core.
what is the other way around if ModelConfiguration is missing.
It's even easier in Core 2.0 now
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
namespace MyApp.DAL.EntityConfigurations
{
public class StudentConfiguration : IEntityTypeConfiguration<Student>
{
public void Configure(EntityTypeBuilder<Student> modelBuilder)
{
modelBuilder.Property(f => f.Name).IsRequired();
}
}
}
Then in your db context:
public DbSet<Student> Students{ get; set; }
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options) { }
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
// Customizations must go after base.OnModelCreating(builder)
builder.ApplyConfiguration(new StudentConfig());
builder.ApplyConfiguration(new SomeOtherConfig());
// etc.
// etc..
}
I've just stumbled across this question as I was searching for the answer myself. I found that it is not (yet?) implemented in EF Core but can be implemented yourself fairly easily.
You can create one of these:
using Microsoft.EntityFrameworkCore.Metadata.Builders;
namespace Microsoft.EntityFrameworkCore
{
public abstract class EntityTypeConfiguration<TEntity> where TEntity : class
{
public abstract void Map(EntityTypeBuilder<TEntity> modelBuilder);
}
public static class ModelBuilderExtensions
{
public static void AddConfiguration<TEntity>(this ModelBuilder modelBuilder, EntityTypeConfiguration<TEntity> configuration) where TEntity : class
{
configuration.Map(modelBuilder.Entity<TEntity>());
}
}
}
And then you can create a configuration for the entity itself: -
using Microsoft.EntityFrameworkCore;
using Project.Domain.Models;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
namespace Project.Persistance.EntityConfigurations
{
public class MyEntityConfiguration : EntityTypeConfiguration<MyEntity>
{
public override void Map(EntityTypeBuilder<MyEntity> modelBuilder)
{
modelBuilder
.Property();//config etc
}
}
}
You can then load all your configurations somewhere (there's probably both a better way and a better place for doing it... but this is what I did): -
using Microsoft.EntityFrameworkCore;
using Project.Domain.Models;
using Project.Persistance.EntityConfigurations;
namespace Project.Persistance
{
public class MyDbContext : DbContext
{
// Normal DbContext stuff here
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.AddConfiguration(new MyEntityConfiguration());
}
}
}