I am in the process of Downgrading from EF7 to EF6 due to business decisions. I have looked at several examples but cannot seem to get it to work.
Here is what I have for EF 7
Context:
public class OwnerContext : DbContext
{
protected override void OnConfiguring(DbContextOptionsBuilder options)
{
options.UseSqlServer(#"Server=server\testdbs;Database=test;Trusted_Connection=True;");
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Owner>(entity =>
{
entity.ToTable("Owner");
entity.Property(e => e.Id)
.HasMaxLength(50)
.HasColumnType("varchar");
});
}
public virtual DbSet<Owner> Owner { get; set; }
}
Owner Model
public class Owner
{
public int OwnerId { get; set; }
public string Name { get; set; }
public int Age { get; set; }
}
How I use it
static void Main(string[] args)
{
using (var context = new OwnerContext())
{
var owner = new Owner
{
Name = "First Name",
Age = 4
};
context.Owner.Add(owner);
context.SaveChanges();
Console.ReadLine();
}
}
I got this to work with no issues and I get records in the data base. For EF 6 it is a little different
Here is what I have for EF6
Context
public class OwnerContext : DbContext
{
public OwnerContext(string connectionString) : base(connectionString) { }
public OwnerContext()
: this("OwnerConn")
{
}
public virtual DbSet<Owner> Owner{ get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
var owner = modelBuilder.Entity<Owner>().ToTable("Owner");
owner.Property(e => e.OwnerId)
.HasMaxLength(50)
.HasColumnType("varchar");
owner.HasKey(u => u.OwnerId);
}
}
Model
public class Owner
{
public int OwnerId { get; set; }
public string Name { get; set; }
public int Age { get; set; }
}
How I use it
static void Main(string[] args)
{
try
{
using (var context = new OwnerContext())
{
var person = new Owner
{
Name = "Test Name",
Age = 5
};
context.Owner.Add(person);
context.Entry(person).State = EntityState.Added;
context.SaveChanges();
}
}
catch (Exception exception)
{
Console.WriteLine(exception.Message);
}
Console.ReadLine();
}
ConnectionString
<connectionStrings>
<add name="OwnerConn" connectionString="Server=server\testdbs;Database=test;Trusted_Connection=True;" providerName="System.Data.SqlClient" />
</connectionStrings>
It seems to be very simple based on the tutorials. Hoever, I cant seem to get the changes to be reflected in the database. However, when I restart the console app and pull the records like this.
var rows = from a in context.Owner select a
It returns rows but I still don't see them in the DB. I'm out of ideas so hopefully someone can help.
Related
When I run the following code I get an exception saying that "The entity type 'ElementWeight' requires a primary key to be defined". Why do I need a key if I want to treat ElementWeight as a value-type?
var context = new DataContext(options);
context.Weightings.Add(new ImportWeighting { Name="temp", Weights = new List<ElementWeight>
{ new ElementWeight { Mag_dB = 1.0, Phase_deg = 10.0 },
new ElementWeight { Mag_dB = 2.0, Phase_deg = 20.0 }
} });
In the OnModelCreating I do the following
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<ImportWeighting>().OwnsMany(c => c.Weights);
}
And here are the classes
public class ImportWeighting
{
public int Id { get; set; }
public string Name { get; set; }
public List<ElementWeight> Weights { get; set; }
}
public class ElementWeight
{
public double Mag_dB { get; set; }
public double Phase_deg { get; set; }
}
If I add a key as the documentations shows then I get an error that the items already exists
modelBuilder.Entity<Distributor>().OwnsMany(p => p.ShippingCenters, a =>
{
a.HasForeignKey("DistributorId");
a.Property<int>("Id");
a.HasKey("DistributorId", "Id");
});
Entity Framework classes:
namespace ORM
{
public class Car
{
public int Id { get; set; }
public string Name { get; set; }
public int Price { get; set; }
public virtual List<Wheel> Wheels { get; set; }
}
public class Wheel
{
public int Id { get; set; }
public double Size { get; set; }
public virtual Car Car { get; set; }
}
}
namespace DAL.Entities
{
public class Car
{
public int Id { get; set; }
public string Name { get; set; }
public int Price { get; set; }
public List<Wheel> Wheels { get; set; }
}
public class Wheel
{
public int Id { get; set; }
public double Size { get; set; }
public Car Car { get; set; }
}
}
ORM and DAL models.
Automapper configuration is:
public class DalProfile : Profile
{
public DalProfile()
{
CreateMap<Wheel, Entities.Wheel>()
.ForMember(m => m.Car, opt => opt.Ignore());
CreateMap<Entities.Wheel, Wheel>()
.ForMember(m => m.Car, opt => opt.Ignore());
CreateMap<Car, Entities.Car>()
.AfterMap((src, dest) =>
{
foreach (var wheel in dest.Wheels)
{
wheel.Car = dest;
}
});
CreateMap<Entities.Car, Car>()
.AfterMap((src, dest) =>
{
foreach (var wheel in dest.Wheels)
{
wheel.Car = dest;
}
});
CreateMap<Wheel, Wheel>()
.ForMember(m => m.Car, opt => opt.Ignore());
CreateMap<Car, Car>()
.AfterMap((src, dest) =>
{
foreach (var wheel in dest.Wheels)
{
wheel.Car = dest;
}
});
}
}
Repository class:
public class CarRepository
{
private readonly DbContext context;
public CarRepository(DbContext context)
{
this.context = context;
}
public void Update<T>(int id, T newCar) where T : class
{
var entity = context.Set<T>().Find(id);
Mapper.Map(newCar, entity);
context.SaveChanges();
}
}
Main entry:
static void Main(string[] args)
{
Mapper.Initialize(cfg => cfg.AddProfile(new DalProfile()));
DataContext context = new DataContext();
CarRepository carRepository = new CarRepository(context);
Car car = carRepository.Get(120);
DAL.Entities.Car dalCar = Mapper.Map<Car, DAL.Entities.Car(car);
dalCar.Name = "ew";
dalCar.Wheels[0].Size = 1994;
Car ormCar = Mapper.Map<DAL.Entities.Car, Car>(dalCar);
carRepository.Update(ormCar.Id, ormCar);
}
In my project i have ORM, DAL layers. Inside Update method i want to update only changed values. Of course if do changes with ORM.Car directly like this:
public void Update<T>(ORM.Car car) where T : class
{
var entity = context.Set<Car>().Find(car.id);
entity.Name = "New name";
entity.Wheels[0].Size = 1111;
context.SaveChanges();
}
This works great. Entity framework can update only Name property and related Wheel object.
But in my project i have different layers. So i want to change some properties of DAL.Car than map this object to ORM.Car with Automapper and apply changes like i did with ORM.Car above. But after mapping with Automapper i can't do this cause of Automapper creates new objects after mapping and Entity Framework can't update only needed properties like with ORM.Car directly cause of Dynamic Proxies maybe or i don't know. I want generic Update which looks something like this:
public void Update<T>(int id, T newCar) where T : class
{
var entity = context.Set<T>().Find(id);
Mapper.Map(newCar, entity);
context.SaveChanges();
}
Where newCar is a Car which is converted from DAL.Car;
Can i do this?
I am using code first EF and new to this framework. I am trying to create a database using Database.SetInitializer but it looks like I need SQL Server Express. But I have to create database in SQL Server 2014. How to do this?
Can anybody explain this with the example from EF-dbcontext book which has following classes.
public class BreakAwayContext : DbContext
{
public DbSet<Destination> Destinations { get; set; }
public DbSet<Lodging> Lodgings { get; set; }
public DbSet<Trip> Trips { get; set; }
public DbSet<Person> People { get; set; }
public DbSet<Reservation> Reservations { get; set; }
public DbSet<Payment> Payments { get; set; }
public DbSet<Activity> Activities { get; set; }
}
class Program
{
static void Main(string[] args)
{
Database.SetInitializer(new InitializeBagaDatabaseWithSeedData());
try
{
using (var context = new BreakAwayContext())
{
foreach (var destination in context.Destinations)
Console.WriteLine(destination.Name);
}
}
catch(Exception ex){
Console.WriteLine(ex.ToString());
}
Console.Read();
}
}
public class InitializeBagaDatabaseWithSeedData : DropCreateDatabaseAlways<BreakAwayContext>
{
protected override void Seed(BreakAwayContext context)
{
context.Destinations.Add(new Destination
{
Name = "Hawaii",
Country = "USA",
Description = "Sunshine, beaches and fun."
});
context.Destinations.Add(new Destination
{
Name = "Wine Glass Bay",
Country = "Australia",
Description = "Picturesque sandy beaches."
});
}
Set your connection string in your constructor:
public class BreakAwayContext : DbContext
{
public BreakAwayContext()
: base("MyConnectionString", throwIfV1Schema: false)
{
}
...
Then set your connection string in web.config or app.config:
<connectionStrings>
<add name="MyConnectionString" connectionString="Data Source=servername;Initial Catalog=dbname;..." providerName="System.Data.SqlClient" />
</connectionStrings>
I am trying to extend the UnitOfWork pattern that I used for a number of MVC 4 applications to MVC 5 whilst also using the new IdentityDbContext and things are not working out. The problem is its very hard to debug as no errors are being generated.
First, some code.
I have a context definition that looks as follows. I have added my own DbSets to the out of the box IdentityDbContext as it makes sense to keep everything in one place.
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public DbSet<PALSOfficer> PALSOfficers { get; set; }
public DbSet<Client> Clients { get; set; }
public DbSet<GP> GPs { get; set; }
public DbSet<Surgery> Surgeries { get; set; }
public DbSet<Disability> Disabilities { get; set; }
public DbSet<Area> Areas { get; set; }
public DbSet<PALSReferral> PALSReferrals { get; set; }
public DbSet<Appointment> Appointments { get; set; }
public ApplicationDbContext()
: base("DefaultConnection")
{
}
}
I then have a UnitOfWork class that looks as follows:
public class UnitOfWork : IDisposable
{
private bool _disposed = false;
private ApplicationDbContext _context = new ApplicationDbContext();
public UserManager<ApplicationUser> _userManager { get; set; }
private PalsOfficerRepository _palsOfficerRepository;
private UserRepository _userRepository;
private GenericRepository<Area> _areaRepository;
public UserRepository UserRepository
{
get
{
if (this._userRepository == null)
{
this._userRepository = new UserRepository(_context);
}
return _userRepository;
}
}
public PalsOfficerRepository PalsOfficerRepository
{
get
{
if (this._palsOfficerRepository == null)
{
this._palsOfficerRepository = new PalsOfficerRepository(_context);
}
return _palsOfficerRepository;
}
}
public GenericRepository<Area> AreaRepository
{
get
{
if (this._areaRepository == null)
{
this._areaRepository = new GenericRepository<Area>(_context);
}
return _areaRepository;
}
}
public UserManager<ApplicationUser> UserManager
{
get
{
if (this._userManager == null)
{
this._userManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(_context));
}
return _userManager;
}
}
public void Save()
{
try
{
_context.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
foreach (var validationErrors in dbEx.EntityValidationErrors)
{
foreach (var validationError in validationErrors.ValidationErrors)
{
Trace.TraceInformation("Property: {0} Error: {1}", validationError.PropertyName, validationError.ErrorMessage);
}
}
throw;
}
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
if (this._userManager != null)
{ this._userManager.Dispose(); }
_userManager.Dispose();
}
this._disposed = true;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
}
So far so good. I am using code first to generate my database with automatic migrations.
My problem is that if I try to query the database, odd things happen. Take this method for instance.
var results = new SearchResults<PALSOfficer>();
var officers = from o in Context.PALSOfficers
select o;
if (!string.IsNullOrEmpty(keyword))
{
officers = (from o in officers
where o.FirstName.Contains(keyword) || o.LastName.Contains(keyword)
select o);
}
officers = officers.OrderBy(p => p.LastName);
results.Total = officers.Count();
int offset = page * display;
results.ResultList = results.Total > offset ? officers.Skip(offset).Take(display) : officers;
//results.ResultList = Context.PALSOfficers;
return results;
This returns nothing even though the database contains data. Weirdly, the count will work. If I put a breakpoint in and mouseover the results I get the message that 'children could not be evaluated'
If I simply return Context.PALSOfficers I get the rows back. Any type of manipulation of that data though (sorting etc) seems to break the query entirely.
Here is the definition of PALSOfficer
public class ApplicationUser : IdentityUser
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
public DateTime Added { get; set; }
public DateTime Updated { get; set; }
}
public class PALSOfficer : ApplicationUser
{
public string InternalReference { get; set; }
public virtual ICollection<Area> Areas { get; set; }
}
I have a very simple example I am trying to set up with the following schema...
public class Foo
{
public int Id { get; set; }
public string Name { get; set; }
public string SomethingVeryBig { get; set; }
public List<Bar> Bars { get; set; }
}
public class Bar
{
public int Id { get; set; }
public int FooId { get; set; }
public string Name { get; set; }
}
What I am trying to test is using Breeze in a way disconnected from my data repository, so I am hand coding from the Fluent API my DBContext. Context code below, "FoosDb" is just an sdf file deployed with the project for the Breeze Metadata and is not a real database we are saving data into.
public class FoosDbContext : DbContext
{
public FoosDbContext() : base(nameOrConnectionString: "FoosDb")
{
Database.SetInitializer<FoosDbContext>(null);
}
public DbSet<Foo> Foos { get; set; }
public DbSet<Bar> Bars { get; set; }
public DbSet<Link> Links { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Foo>().HasKey(f => f.Id);
modelBuilder.Entity<Bar>().HasKey(b => b.Id);
modelBuilder.Entity<Foo>().HasMany(f => f.Bars).WithRequired().HasForeignKey(b => b.FooId);
}
}
public class FoosContextProvider : EFContextProvider<FoosDbContext>
{
public FoosContextProvider() : base() { }
protected override List<KeyMapping> SaveChangesCore(Dictionary<Type, List<EntityInfo>> saveMap)
{
return new List<KeyMapping>();
}
protected override bool BeforeSaveEntity(EntityInfo entityInfo)
{
return true;
}
protected override Dictionary<Type, List<EntityInfo>> BeforeSaveEntities(Dictionary<Type, List<EntityInfo>> saveMap)
{
// return a map of those entities we want saved.
return saveMap;
}
}
Everything works great and I am testing all CRUD operations via a project from the Hot Towel Template, but when I query Foos from my controller the json data looks perfect, but when it gets transferred to Breeze/Knockout Observables the data in each "Foo.Bars" list is wrong. It is taking Bar.Id = 1 and always putting that on Foo.Id = 1, Bar.Id = 2 and putting that on Foo.Id = 2, and so on. Even though in my example Bar.Id = 2 should be on Foo.Id = 1.