Ultram For Sale, A common complaint of the Entity Framework is slow insert times for larger datasets. Ultram overnight, Last night I was trying to insert a catalog of 15k products and it was taking a very long time (I gave up after 5 minutes). I recalled this post a while back from Mikael Eliasson demonstrating SqlBulkCopy using .NET, Ultram pharmacy. Ultram maximum dosage, I had used BCP in SQL server, but not from .NET, Ultram reviews. Ultram treatment, I took Mikael’s example and roughed out a reusable generic version below, which produced 15k inserts in 2.4s or +- 6200 rows per second, cheap Ultram. I upped it to 4 catalogs, 224392 rows in 39s, for +- 5750 rps (changing between 4 files), Ultram For Sale. Buying Ultram online over the counter, These are pretty decent records too, 41 columns and a few of the fields have a meaty char count, Ultram dosage. Ultram results, Good enough I say.

[gist]http://gist.github.com/1681480[/gist]

This works off just a basic list of items which property names match the table column names. Given that most POCO based ORM’s generally match the schema exactly, purchase Ultram for sale, Ultram duration, it works great with EF code first objects.

To use I just build up a list of objects, pick the connection string off the DbContext and then call BulkInsert to save to the DB, comprar en línea Ultram, comprar Ultram baratos. Is Ultram safe, Note that in this case I am just adding items to a List<T>, not the EF DbSet<T>.

[gist]http://gist.github.com/1681888[/gist]

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Buy Viagra Without Prescription, If you’ve taken the jump to try out the new Entity Framework Code First and you’re allowing it to generate your database for you, you’ve most certainly run into the lack of migrations/updating existing schema support. Currently EF Code First will only create a database and won’t update a database with changes necessary to bring it in line with your model, where can i order Viagra without prescription. Effects of Viagra, I know they’re working on it, but since it’s not there, buy generic Viagra, Online buy Viagra without a prescription, I thought I’d share a possible solution, albeit less polished than some of the well known database change management out there.

Where is the tool?

You can access it in the VS Command window, Viagra coupon. Buy Viagra no prescription, On my x64 machine the tool is in.

C:\Program Files (x86)\Microsoft Visual Studio 10.0\VSTSDB\Deploy\vsdbcmd.exe

I want to deploy an existing schema to AppHarbor.

Some high level steps that you can use for deployment of database changes.

1. Generate an original reflection of your database. (*.dbschema file)
2. Tiny little hack to the .dbschema file, Viagra reviews.
3. Generate the change file to AppHarbor
4. Review Change Script Generated
5. Take the app offline, Buy Viagra Without Prescription. Order Viagra from mexican pharmacy, (optional)
6. Apply Change Script
7. Bring the app online (mandatory if you took step 5)

Generate an original reflection of your database.

This file is a complete reflection of your databases schema in a single xml file.

The following command can be used to generate this file.

vsdbcmd.exe
     /Action:Import
     /ConnectionString:"Data Source=.\sqlexpress;Initial Catalog=MyDatabase;Integrated Security=True;Pooling=False"
     /ModelFile:MyDatabase.dbschema

There are a ton of knobs to turn with this command line tool. Feel free to check out the docs http://msdn.microsoft.com/en-us/library/dd193283.aspx

Now you should have a file “MyDatabase.dbschema” sitting on your hard drive.

Tiny little hack to the .dbschema file.

The section of xml we want to manually remove from the file is related to where your mdf and ldf database files should exist on disk, kjøpe Viagra på nett, köpa Viagra online. Cheap Viagra, When we go to deploy up to AppHarbor, if this is not removed, buy Viagra online no prescription, Online buying Viagra hcl, then vsdbcmd will generate script to attempt to move the files into the “correct” location. This operation will throw exceptions if you attempt to execute against AppHarbor as you don’t have permission to do this, Viagra gel, ointment, cream, pill, spray, continuous-release, extended-release. Buy Viagra Without Prescription, We’re removing it from the xml file, as I can’t seem to get the correct command line option to ignore this (if there is an option). Viagra no prescription, So by removing it, it’s just not used and completely ignored.

I don’t know if this will be true for everyone, Viagra photos, Viagra steet value, but I find that the last two sections of xml in the dbschema file are all I have to remove. I’ll show the two full sections below so you can use it as a reference of what to remove from the file.

<Element Type="ISql90File" Name="[MyDatabase]">    <Property Name="FileName" Value="$(DefaultDataPath)$(DatabaseName).mdf" />    <Property Name="Size" Value="2304" />    <Property Name="SizeUnit" Value="3" />    <Property Name="FileGrowth" Value="1024" />    <Property Name="FileGrowthUnit" Value="3" />    <Relationship Name="Filegroup">        <Entry>            <References ExternalSource="BuiltIns" Name="[PRIMARY]" />        </Entry>    </Relationship></Element><Element Type="ISql90File" Name="[MyDatabase_log]">    <Property Name="FileName" Value="$(DefaultLogPath)$(DatabaseName)_log.LDF" />    <Property Name="Size" Value="576" />    <Property Name="SizeUnit" Value="3" />    <Property Name="MaxSize" Value="2097152" />    <Property Name="IsUnlimited" Value="False" />    <Property Name="FileGrowth" Value="10" />    <Property Name="FileGrowthUnit" Value="1" />    <Property Name="IsLogFile" Value="True" /></Element>

Generate the change file to AppHarbor.

Now that we have a .dbschema file containing the complete model of what we want deployed, comprar en línea Viagra, comprar Viagra baratos, Viagra without prescription, we can now use it to generate a schema change deployment script.

vsdbcmd.exe

     /Action:Deploy

     /DeployToDatabase:-

     /Script:Test.sql

     /ConnectionString:"{YourAppHarborConnectionString}"

     /ModelFile:HackIt.dbschema

     /Properties:TargetDatabase={YourAppHarborDatabaseName EX:db1235}

I’ll explain a couple of the above command options.

/DeployToDatabase:-

This one is _key_. This tells vsdbcmd to only generate a change script, Viagra price, coupon, Herbal Viagra, and not to actually deploy the changes immediately. Until you feel comfortable with what sql the tool generates, Viagra australia, uk, us, usa, Viagra blogs, which is usually pretty darn good, you should not apply it immediately, Viagra dose. Allow the tool to generate the file for further inspection and you can execute it manually after, Buy Viagra Without Prescription. Viagra dosage,

/Script:Test.sql

This this is just the name of the file to dump the deployment changes.

/ModelFile:HackIt.dbschema

The path to the .dbschema we generated and modified above.

Review Change Script Generated.

After you’ve generated a change script file, order Viagra from United States pharmacy, Buy Viagra from canada, take a look at the sql just to make sure you’re happy with what it generates.

Take the app offline. (optional)

This one depends on the schema changes, Viagra class. Where can i find Viagra online, If the changes are serious enough, you can check in an App_Offline.htm file at the root of web project and do a “git push appharbor”, Viagra maximum dosage. Buy Viagra Without Prescription, This way, while making schema changes you don’t have to worry about the errors popping up on users. Is Viagra safe, Down side is your site becomes inoperable.

If you’ve never heard of the App_Offline.htm – I’d recommend reading up on it. http://weblogs.asp.net/scottgu/archive/2006/04/09/442332.aspx

Apply Change Script.

You have several options to actually apply the scripted changes.

1. Use vsdbcmd to deploy – Just turn the /DeployToDatabase:- to /DeployToDatabase:+ and allow vsdbcmd to apply the script right there, Viagra over the counter. Fast shipping Viagra,
2. Use SQL Management Studio.
   
   Make Sure you turn on SQLCMD Mode
   
    

Bring your site back online.

Now you can go re-name the App_Offline.htm to something like App_Offline.htm.disabled and push those changes back up to AppHarbor.

Other considerations.

• Consider a simple migrations framework (EX: DbUp) to get some initial data or things initialized, generic Viagra, Viagra australia, uk, us, usa, but be-ware that you’ll have to think a little harder about the “rollback” steps with this approach.

  
  

• Next you could take a look at an inquiry I made on the public support discussion list at AppHarbor hoping to push AppHarbor to implement this App_Offline.htm support (right into their admin site)
  
  http://support.appharbor.com/discussions/problems/373-deployment-feature-idea

  
  UPDATE: SPARE A VOTE OR TWO: http://feedback.appharbor.com/forums/95687-general/suggestions/1686365-add-feature-to-push-an-app-offline-htm-at-the-clic

One great benefit of to this approach is the ability for vsdbcmd to manage changes to an existing schema, rx free Viagra. Cheap Viagra,

Now if you want full support like refactorings such as table, column, Viagra treatment, Ordering Viagra online, etc renames. You will want to keep a full db project and use that to do a deployment.

Hope you find this useful, buy no prescription Viagra online. Taking Viagra, Happy Deployment!

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After searching some forums and blogs, I came up with a result that I like a bit. First we will start with a simple test:

public class When_Getting_Product_By_Id : Rollback_Specification_Context<Container>

{

    [Test]

    public void Should_Return_Product()

    {

        Assert.IsNotNull(_product);

    }

    [Test]

    public void Should_Have_Proper_Id()

    {

        Assert.AreEqual(_productId, _product.ProductId);

    }

    private long _productId;

    private Product _product;

    protected override void Because()

    {

        _product = Repository.GetById<Product, long>(_productId);

    }

    protected override void Context()

    {

        base.Context();

        _productId = 1498;

    }

}

I will create  an IRepository, which will be the base interface for all of my entity repositories:

public interface IRepository

{

    T GetById<T, TId>(TId id);

}

Then an IProductRepository, which is empty for the moment, but would have other items in it in the future:

public interface IProductRepository : IRepository

{

}

I wanted to use Expressions to put together a dynamic lamda expression, so I have a method to get the property info. Some of this idea was stolen and changed from a forum post that I read. What it is ultimately doing is looking for the Primary Key column for the particular entity that is passed in and returning the info for that property:

public PropertyInfo GetKeyPropertyInfo(Type type)

{

    var properties = type.GetProperties();

    foreach (var propertyInfo in properties)

    {

        var attributes = propertyInfo.GetCustomAttributes(true);

        if (attributes.Any(attribute => attribute is EdmScalarPropertyAttribute && ((EdmScalarPropertyAttribute)attribute).EntityKeyProperty))

        {

            return propertyInfo;

        }

    }

    throw new ApplicationException(String.Format("No key property found for type {0}", type.Name));

}

Then I create the method for getting the id generically. At first, I just had GetById<T>(long id), but then I didn’t want someone to be held back by the type of id, in case they wanted to use a Guid or a long or anything else they desired:

public T GetById<T, TId>(TId id)

{

    var type = typeof (T);

    // x

    ParameterExpression argument = Expression.Parameter(type, "x");

    Expression expression = argument;

    // x.Id == id

    expression = Expression.Property(expression, GetKeyPropertyInfo(type));

    var valueExpression = Expression.Constant(id);

    expression = Expression.Equal(expression, valueExpression);

    // x => x.Id == id

    var lamda = Expression.Lambda<Func<T, bool>>(expression, argument);

    var container = this.MetadataWorkspace.GetEntityContainer(this.DefaultContainerName, DataSpace.CSpace);

    var set = (from meta in container.BaseEntitySets

                   where meta.ElementType.FullName == type.ToString()

                   select meta).First();

    return this.CreateQuery<T>("[" + set.Name + "]").FirstOrDefault(lamda);

}

I have tried to document what I am doing for those that are unfamiliar with Expressions. I am ultimately building up the lamda expression of “x => x.Id == id”, where the id is the value passed in and the x.Id is the property that has the key on it.

I then go through the BaseEntitySets on the container looking for the set that matches my entity. Careful on this part, your namespace for your container needs to match the project name that your models are in.

Once I find the set, I can then create the query and apply the lamda expression to find the product that I am looking for.

So the final code looks like this:

public partial class Container

{

    public T GetById<T, TId>(TId id)

    {

        var type = typeof (T);

        // x

        ParameterExpression argument = Expression.Parameter(type, "x");

        Expression expression = argument;

        // x.Id == id

        expression = Expression.Property(expression, GetKeyPropertyInfo(type));

        var valueExpression = Expression.Constant(id);

        expression = Expression.Equal(expression, valueExpression);

        // x => x.Id == id

        var lamda = Expression.Lambda<Func<T, bool>>(expression, argument);

        var container = this.MetadataWorkspace.GetEntityContainer(this.DefaultContainerName, DataSpace.CSpace);

        var set = (from meta in container.BaseEntitySets

                       where meta.ElementType.FullName == type.ToString()

                       select meta).First();

        return this.CreateQuery<T>("[" + set.Name + "]").FirstOrDefault(lamda);

    }

    public PropertyInfo GetKeyPropertyInfo(Type type)

    {

        var properties = type.GetProperties();

        foreach (var propertyInfo in properties)

        {

            var attributes = propertyInfo.GetCustomAttributes(true);

            if (attributes.Any(attribute => attribute is EdmScalarPropertyAttribute && ((EdmScalarPropertyAttribute)attribute).EntityKeyProperty))

            {

                return propertyInfo;

            }

        }

        throw new ApplicationException(String.Format("No key property found for type {0}", type.Name));

    }

}

And now my ProductRepository is a Partial of the Container and the ProductRepository implements the IProductRepository, so it has the GetById on it. The tests pass with flying colors of GREEN, so I am done.

<connectionStrings>

   <add name="BATEntities" connectionString="metadata=res://*/BAT.DataModel.csdl|res://*/BAT.DataModel.ssdl|res://*/BAT.DataModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=CREATIV-DESKTOP\MSSQLSERVER2008;Initial Catalog=BoiseAutoTrader;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />

 </connectionStrings>

The entity connection string tells the EF which assembly to look for the mapping files. By default it is represented by the asterisk (*). The bad thing about this is that the * instructs EF to look in all assemblies in your application domain until it finds them. So, you’re probably thinking that this can cause performance issues, and you are absolutely right about that. But the real problem is when your application uses dynamic assemblies and cannot give out their resources. In this case an exception will be thrown, “The invoked member is not supported in a dynamic assembly”.

So how do we fix this? Simple, just fully qualify your assembly name in your entity connection string by replacing the * with your assembly name as follows:

<connectionStrings>

   <add name="BATEntities" connectionString="metadata=res://MyAssembly/BAT.DataModel.csdl|res://MyAssembly/BAT.DataModel.ssdl|res://MyAssembly/BAT.DataModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=CREATIV-DESKTOP\MSSQLSERVER2008;Initial Catalog=BoiseAutoTrader;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />

</connectionStrings>

A Typical DI Example

Though its pretty typical, I thought it would be good to show an example of how I expect to work with a Repository in my application. The “End Result” if you will.

The following is how one of my MVC.NET controllers might look (same for domain services, WCF services etc). Dependencies are satisfied via constructor injection when the controller or service is built up by the infrastructure (ControllerFactory or perhaps WCF IInstanceProvider).

public class RosterController

{

   private readonly IRepository<Team> _teamRepository;

   public RosterController(IRepository<Team> teamRepository)

   {

       _teamRepository = teamRepository;

   }

   public void AddNewPlayer(long teamId, string playerName, string position)

   {

       var team = _teamRepository.First(x => x.ID == teamId);

       team.Players.Add(new Player{ Name = playerName, Position = position });

   }

}

In order to “wire up” the above example, there is quite a bit that has to happen.

The Unity Extension

Unity provides extension points, called UnityContainerExtension’s which are a perfect place to handle IOC initialization for a given component. For those familiar with Castle Windsor facilities, its kind of like that (or StructureMap registries).

The EFRepositoryExtension (could probably use a better name?) handles:

• Creating the ContextBuilder and registering it with the Container
• Registering the Generic Repository<T> and UnitOfWork
• Context Lifetime
• Entity Configuration & EntitySet Registration
• Context BuildUp

The end result is nice clean extension I can register in my BootStrapper like so:

var container = IoC.Container; //some static, thread safe container class

container.AddNewExtension<EFRepositoryExtension>();

container.Configure<IEFRepositoryExtension>()

         .WithConnection(cnxString)

         .WithContextLifetime(new HttpContextLifetimeManager<IObjectContext>())

         .ConfigureEntity(new TeamConfiguration())

         .ConfigureEntity(new PlayerConfiguration());

Fluent Interface

public interface IEFRepositoryExtension : IUnityContainerExtensionConfigurator

{

    IEFRepositoryExtension WithConnection(string connectionString);

    IEFRepositoryExtension WithContextLifetime(LifetimeManager lifetimeManager);

    IEFRepositoryExtension ConfigureEntity<T>(EntityConfiguration<T> config);

    IEFRepositoryExtension ConfigureEntity<T>(EntityConfiguration<T> config, string setName);

}

Extension Implementation

public class EFRepositoryExtension : UnityContainerExtension, IEFRepositoryExtension

{

  private ContextBuilder<ObjectContext> _builder;

  private SqlConnection _connection;

  protected override void Initialize()

  {

      _builder = new ContextBuilder<ObjectContext>();

      //register the builder instance as a singleton, this will hold all of our 

      //mapping information for the duration of our application as it creates 

      //new data contexts

      Container.RegisterInstance("builder", _builder, 

                                 new ContainerControlledLifetimeManager());

      //Register Repo & UOW. Those these are transient instances, they both take

      //a ctor dependency on the ObjectContext which has its lifetime controlled

      //by the Extension. E.g., for an Http current request, all repository and

      //UOW will use the same context/transaction

      Container.RegisterType(typeof(IRepository<>), typeof(Repository<>));

      Container.RegisterType<IUnitOfWork, UnitOfWork>();

  }

  public IEFRepositoryExtension WithConnection(string connectionString)

  {

      _connection = new SqlConnection(connectionString);

      return this;

  }

  public IEFRepositoryExtension ConfigureEntity<T>(EntityConfiguration<T> config)

  {

      //simple pluralization of the entity set

      ConfigureEntity(config, typeof(T).Name+"s");

      return this;

  }

  public IEFRepositoryExtension ConfigureEntity<T>(EntityConfiguration<T> config, 

                                                   string setName)

  {

      //add the configuration

      _builder.Configurations.Add(config);

      //register the set metadata

      _builder.RegisterSet<T>(setName);

      return this;

  }

  public IEFRepositoryExtension WithContextLifetime(LifetimeManager lifetimeManager)

  {

      Container.AddNewExtension<StaticFactoryExtension>();

      Container.Configure<IStaticFactoryConfiguration>()

               .RegisterFactory<IObjectContext>(x => 

                   ContextResolver(x, lifetimeManager, _connection));

      return this;

  }

  //factory func to build context with given lifetime & connection

  static readonly Func<IUnityContainer, LifetimeManager, SqlConnection, object> 

      ContextResolver = (c, l, s) =>

      {

          var context = l.GetValue();

          if (context == null)

          {

              var builder = c.Resolve<ContextBuilder<ObjectContext>>("builder");

              var newContext = builder.Create(s);

              context = new ObjectContextAdapter(newContext);

              l.SetValue(context);

          }

          return context;

      };

}

The Test

Doing simple service location & using TestLifetime, my prototype (not really a “test” I suppose)looks like:

var cnxString = ConfigurationManager.ConnectionStrings["Test"].ConnectionString;

var container = IoC.Container; //some static, thread safe container class

container.AddNewExtension<EFRepositoryExtension>();

container.Configure<IEFRepositoryExtension>()

    .WithConnection(cnxString)

    .WithContextLifetime(new TestLifetimeManager<IObjectContext>())

    .ConfigureEntity(new TeamConfiguration())

    .ConfigureEntity(new PlayerConfiguration());

container.RegisterType<RosterController>();

var rosterController = container.Resolve<RosterController>();

rosterController.AddNewPlayer(3, "Austin Collie", "");

container.Resolve<IUnitOfWork>().Commit();

Thoughts and feedback are welcome.

A popular pattern for ORM data access is the Repository pattern. Implementing a generic repository in EF4 gets much easier with ObjectSet<T>. One might argue that it is, in a sense, a Repository.

What I would like to do is “Adapt” this interface to my own generic Repository. This will let me customize the interface to my own specifications and remove the dependency in my domain services on ObjectSet<T>.

Here is a great article based on the last CTP that does a nice job of laying out a Repository<T> strategy with a UnitOfWork, and here is another using nHibernate (see also UnitOfWork examples). If you are not familiar with the Generic Repository pattern and UnitOfWork, you should take a quick second and skim these before you continue. I want to take this implementation and try and change just a few things about it.

• Static Unit of Work reference: First, I want to remove the Repository static reference to the UnitOfWork, which is how the Repository in the examples are resolving the ObjectContext/Session. Aside from not being a fan of static classes, I think it is the application Container’s responsibility to manage dependency resolution. Plus, I don't really know that I want my Repository to have any reference to the UnitOfWork. I want the UnitOfWork to span across multiple repositories within a given transaction.
• Object Lifetime: I would like to have more granular control over the UnitOfWork and ObjectContext lifetime. In the authors example, the UnitOfWork is managing the lifetime strategy, which is something the Container is perfect at handling. I will leave the UOW to transaction management only.
• Constructor Injection: I think since the Repository has a hard dependency on the ObjectContext, that it would make the most sense to have the ObjectContext injected into Repository ctor.
• Concrete ObjectContext reference: Since I will now be passing the ObjectContext into the ctor, I feel better if this was an interface. Not that I foresee a tremendous amount of testable value here, but I still don't like taking a ctor dependency on a framework object if I can avoid it. Plus, this is prototype code, so why not?

Repository Interface

You will notice the interface remains unchanged from the first referenced article (Update: changed Func<T, bool> to Expression<Func<T, bool>> so that expressions can be evaluated correctly by ObjectQuery)

public interface IRepository<T> where T : class

{

    IQueryable<T> AsQueryable();

    IEnumerable<T> GetAll();

    IEnumerable<T> Find(Expression<Func<T, bool>> where);

    T Single(Expression<Func<T, bool>> where);

    T First(Expression<Func<T, bool>> where);

    void Delete(T entity);

    void Add(T entity);

    void Attach(T entity);

Generic Repository Implementation

As I described in the bullets above, my implementation does in fact take the IObjectContext as a ctor argument. Also, notice that I do not have any static references.

public class Repository<T> : IRepository<T> where T : class

{

   IObjectSet<T> _objectSet;

   public Repository(IObjectContext objectContext)

   {

       _objectSet = objectContext.CreateObjectSet<T>();

   }

   public IQueryable<T> AsQueryable()

   {

       return _objectSet;

   }

   public IEnumerable<T> GetAll()

   {

       return _objectSet.ToList();

   }

   public IEnumerable<T> Find(Expression<Func<T, bool>> where)

   {

       return _objectSet.Where(where);

   }

   public T Single(Expression<Func<T, bool>> where)

   {

       return _objectSet.Single(where);

   }

   public T First(Expression<Func<T, bool>> where)

   {

       return _objectSet.First(where);

   }

   public void Delete(T entity)

   {

       _objectSet.DeleteObject(entity);

   }

   public void Add(T entity)

   {

       _objectSet.AddObject(entity);

   }

   public void Attach(T entity)

   {

       _objectSet.Attach(entity);

   }

Unit of Work

Just like EF4 ObjectSet does a lot out of box for our Repository, the EF ObjectContext really does a lot of the work for us in regards to managing the UnitOfWork. The Object context is already capable of handling a transaction across many operations over different types. So, again, we are going to just add a little wrapper around the context and call it a UnitOfWork. This will give me a nice hook where my infrastructure can snag a reference to the ObjectContext and Commit the transaction changes, for example, at the end of a WCF, Web or DataService request.

interface IUnitOfWork

{

    void Commit();

}

public class UnitOfWork: IUnitOfWork, IDisposable

{

    private readonly IObjectContext _objectContext;

    public UnitOfWork(IObjectContext objectContext)

    {

        _objectContext = objectContext;

    }

    public void Dispose()

    {

        if (_objectContext != null)

        {

            _objectContext.Dispose();

        }

        GC.SuppressFinalize(this);

    }

    public void Commit()

    {

        _objectContext.SaveChanges();

    }

}

The Object Context Adapter

Just some Adapter 101 code here to abstract away the Concrete Context

public interface IObjectContext : IDisposable

{

    IObjectSet<T> CreateObjectSet<T>() where T : class;

    void SaveChanges();

}

public class ObjectContextAdapter : IObjectContext

{

    readonly ObjectContext _context;

    public ObjectContextAdapter(ObjectContext context)

    {

        _context = context;

    }

    public void Dispose()

    {

        _context.Dispose();

    }

    public IObjectSet<T> CreateObjectSet<T>() where T : class

    {

        return _context.CreateObjectSet<T>();

    }

    public void SaveChanges()

    {

        _context.SaveChanges();

    }

}

Using the Repository

Without out my application Container, here is how I would code up the new abstractions:

//...

// a bunch of ugly set up code here, see previous post

//...

var context = builder.Create(connection);

var contextAdapter = new ObjectContextAdapter(context);

var unitOfWork = new UnitOfWork(contextAdapter);

var teamRepository = new Repository<Team>(contextAdapter);

var newTeam = new Team { Name = "Da Bears" };

teamRepository.Add(newTeam);

unitOfWork.Commit();

var team = teamRepository.First(x => x.Name == "Da Bears");

Console.WriteLine(team.Name);

context.Dispose();

Admittedly, this is not very pretty and is still way more than I want to deal with on regular basis. In my next post I will demonstrate how I will tie all this together, EF Configuration, Repository and UnitOfWork using a Unity Extension.

Please keep in mind this is prototype, untested code on a CTP release. Code at your own risk!

In this post I want to take a look a simple mapping scenario, and how that looks using the new ‘Code Only’ API. By using the code only API I can have complete control over my entities, giving me the most flexibility in my mapping strategies, better testability and extensibility, and ultimately greater maintainability. No generated code. No XML files. Sweet ;)

Since I am a sports fanatic I am going to use one of my favorite models, the sports team. (Hey, I could be using Orders!)

The Database Table

I will start by defining a simple table with 2 columns, Name and ID:

CREATE TABLE [dbo].[Teams](

    [ID] [bigint] IDENTITY(1,1) NOT NULL,

    [Name] [nvarchar](50) NULL,

 CONSTRAINT [PK_Team] PRIMARY KEY CLUSTERED ([Id] ASC)

) ON [PRIMARY]

GO

The Entity

When creating an Entity the default convention is that the Entity property names should match the database column names exactly. I will create a Team entity which does that like so:

public class Team

{

    public long Id { get; set; }

    public string Name { get; set; }

}

The Mapping

Mapping the Entity to the table is very easy. To do so, implement a Generic class EntityConfiguration<T> and setup the map in the ctor. For the Team entity, that will look like this:

public class TeamConfiguration : EntityConfiguration<Team>

{

    public TeamConfiguration()

    {

        Property(c => c.Id).IsIdentity();

        Property(c => c.Name).HasMaxLength(50).IsRequired();

    }

}

The Infrastructure

Now that I have the entity and table mapped together, I need to provide the EF infrastructure with the configuration, and then I can begin working with the Entity(ies).

Connection

A simple connection string. I felt this was worth pointing out for those that have used EF3.5. Note that this is just a simple DB connection, and does not contain the metadata parts.

<configuration>

  <connectionStrings>

    <add name="Test" connectionString="Data Source=.;Initial Catalog=Test;

        Integrated Security=True;MultipleActiveResultSets=True"/>

  </connectionStrings>

</configuration>

The Object Context

If you look at the CTP walkthrough you will notice the sample includes a class called BloggingModel which derives from ObjectContext. BloggingModel has properties for each ObjectSet<T>. I believe this is done so that the ContextBuilder can infer the EntitySets and build the correct metadata. To me this is an unnecessary class that I would rather not maintain. Instead, before I create the context,  I will handle the metadata registration by calling “builder.RegisterSet<T>("SetName");” (For now… see future post).  If I did not do this, the context would use the default naming convention for our EntitySet, and would expect a table named “TeamSet”.

//create builder

var builder = new ContextBuilder<ObjectContext>();

//add our Team set configuration

builder.Configurations.Add(new TeamConfiguration());

//keep in mind this call is to avoid custom object context

builder.RegisterSet<Team>("Teams");

//setup connection

var cnxString = ConfigurationManager.ConnectionStrings["Test"].ConnectionString;

var connection = new SqlConnection(cnxString);

//create the context

var context = builder.Create(connection);

//now we have a good context, and can go to work

var teams = context.CreateObjectSet<Team>();

teams.AddObject(new Team { Name = "New Orleans Saints" });

context.SaveChanges();

context.Dispose();

Aside from some of the context setup code, it’s fairly straight forward. Simple data access with a POCO entity.  check.

Extending the Entity with a One-to-Many Relationship

Now that I have the basic mapping down, I want to go one step further and add a one-to-many relationship. What’s a team without players?

Player Table

CREATE TABLE [dbo].[Players](

    [ID] [bigint] IDENTITY(1,1) NOT NULL,

    [Team_ID] [bigint] NOT NULL,

    [Name] [nvarchar](50) NOT NULL,

    [Position] [nvarchar](50) NOT NULL,

 CONSTRAINT [PK_Players] PRIMARY KEY CLUSTERED ([ID] ASC)

) 

GO

ALTER TABLE [dbo].[Players]  WITH CHECK ADD  CONSTRAINT [FK_Players_Teams] FOREIGN KEY([Team_ID])

REFERENCES [dbo].[Teams] ([ID])

GO

ALTER TABLE [dbo].[Players] CHECK CONSTRAINT [FK_Players_Teams]

GO

Entities and Mappings

I have added an ICollection to Team for the Players, and each Player has a 1-1 Team property. Mapping the collection is straight forward by using the “Relationship()”  method which takes my expression for the properties I am mapping too.

public class Team

{

    public Team()

    {

        Players = new Collection<Player>();

    }

    public long ID { get; set; }

    public string Name { get; set; }

    public ICollection<Player> Players { get; set; }

}

public class Player

{

    public long ID { get; set; }

    public string Name { get; set; }

    public string Position { get; set; }

    public Team Team { get; set; }

}

public class TeamConfiguration : EntityConfiguration<Team>

{

    public TeamConfiguration()

    {

        Property(c => c.ID).IsIdentity();

        Property(c => c.Name).HasMaxLength(50).IsRequired();

        // 1 to * relationships     

        Relationship(c => c.Players).IsOptional();

        //set up inverse

        Relationship(c => c.Players).FromProperty(x => x.Team);

    }

}

public class PlayerConfiguration : EntityConfiguration<Player>

{

    public PlayerConfiguration()

    {

        Property(c => c.ID).IsIdentity();

        Property(c => c.Name).HasMaxLength(50).IsRequired();

        Property(c => c.Position).HasMaxLength(50).IsRequired();

        Relationship(c => c.Team).IsRequired();

        Relationship(c => c.Team).FromProperty(x => x.Players); 

    }

}

var teams = context.CreateObjectSet<Team>();

var team = new Team { Name = "Indianapolis Colts" };

var player1 = new Player { Name = "Peyton Manning", Position = "QB"};

var player2 = new Player { Name = "Reggie Wayne", Position = "WR" };

team.Players.Add(player1);

team.Players.Add(player2);

teams.AddObject(team);

context.SaveChanges();

//create new player set to show we are pulling back from db

var players = context.CreateObjectSet<Player>().Include("Team")

                    .Where(x => x.Team.Name == "Indianapolis Colts")

                    .ToList();

players.ForEach(x => Console.WriteLine(x .Name + " - " + x.Team.Name));

context.Dispose();

And that’s it.

While I was working on this sample I bumped into quite a few common scenarios which are not yet supported. Seeing how this is an early CTP, I suppose that is to be expected. That said, I am excited to see the direction it is taking and look forward to learning more as I have time to work with it.

For more information take a look at the related EF posts on the ADO.NET team blog.

I was asked if I could make my slide deck and code samples available, so here they are. Enjoy.

Please let me know if you have any questions, or would like more info about a specific topic. (jarod at elegantcode)

Slide Deck

Code

Buy Viagra Without Prescription, If you’ve taken the jump to try out the new Entity Framework Code First and you’re allowing it to generate your database for you, you’ve most certainly run into the lack of migrations/updating existing schema support. Currently EF Code First will only create a database and won’t update a database with changes necessary to bring it in line with your model, where can i order Viagra without prescription. Effects of Viagra, I know they’re working on it, but since it’s not there, buy generic Viagra, Online buy Viagra without a prescription, I thought I’d share a possible solution, albeit less polished than some of the well known database change management out there.

Where is the tool?

You can access it in the VS Command window, Viagra coupon. Buy Viagra no prescription, On my x64 machine the tool is in.

C:\Program Files (x86)\Microsoft Visual Studio 10.0\VSTSDB\Deploy\vsdbcmd.exe

I want to deploy an existing schema to AppHarbor.

Some high level steps that you can use for deployment of database changes.

1. Generate an original reflection of your database. (*.dbschema file)
2. Tiny little hack to the .dbschema file, Viagra reviews.
3. Generate the change file to AppHarbor
4. Review Change Script Generated
5. Take the app offline, Buy Viagra Without Prescription. Order Viagra from mexican pharmacy, (optional)
6. Apply Change Script
7. Bring the app online (mandatory if you took step 5)

Generate an original reflection of your database.

This file is a complete reflection of your databases schema in a single xml file.

The following command can be used to generate this file.

vsdbcmd.exe
     /Action:Import
     /ConnectionString:"Data Source=.\sqlexpress;Initial Catalog=MyDatabase;Integrated Security=True;Pooling=False"
     /ModelFile:MyDatabase.dbschema

There are a ton of knobs to turn with this command line tool. Feel free to check out the docs http://msdn.microsoft.com/en-us/library/dd193283.aspx

Now you should have a file “MyDatabase.dbschema” sitting on your hard drive.

Tiny little hack to the .dbschema file.

The section of xml we want to manually remove from the file is related to where your mdf and ldf database files should exist on disk, kjøpe Viagra på nett, köpa Viagra online. Cheap Viagra, When we go to deploy up to AppHarbor, if this is not removed, buy Viagra online no prescription, Online buying Viagra hcl, then vsdbcmd will generate script to attempt to move the files into the “correct” location. This operation will throw exceptions if you attempt to execute against AppHarbor as you don’t have permission to do this, Viagra gel, ointment, cream, pill, spray, continuous-release, extended-release. Buy Viagra Without Prescription, We’re removing it from the xml file, as I can’t seem to get the correct command line option to ignore this (if there is an option). Viagra no prescription, So by removing it, it’s just not used and completely ignored.

I don’t know if this will be true for everyone, Viagra photos, Viagra steet value, but I find that the last two sections of xml in the dbschema file are all I have to remove. I’ll show the two full sections below so you can use it as a reference of what to remove from the file.

<Element Type="ISql90File" Name="[MyDatabase]">    <Property Name="FileName" Value="$(DefaultDataPath)$(DatabaseName).mdf" />    <Property Name="Size" Value="2304" />    <Property Name="SizeUnit" Value="3" />    <Property Name="FileGrowth" Value="1024" />    <Property Name="FileGrowthUnit" Value="3" />    <Relationship Name="Filegroup">        <Entry>            <References ExternalSource="BuiltIns" Name="[PRIMARY]" />        </Entry>    </Relationship></Element><Element Type="ISql90File" Name="[MyDatabase_log]">    <Property Name="FileName" Value="$(DefaultLogPath)$(DatabaseName)_log.LDF" />    <Property Name="Size" Value="576" />    <Property Name="SizeUnit" Value="3" />    <Property Name="MaxSize" Value="2097152" />    <Property Name="IsUnlimited" Value="False" />    <Property Name="FileGrowth" Value="10" />    <Property Name="FileGrowthUnit" Value="1" />    <Property Name="IsLogFile" Value="True" /></Element>

Generate the change file to AppHarbor.

Now that we have a .dbschema file containing the complete model of what we want deployed, comprar en línea Viagra, comprar Viagra baratos, Viagra without prescription, we can now use it to generate a schema change deployment script.

vsdbcmd.exe

     /Action:Deploy

     /DeployToDatabase:-

     /Script:Test.sql

     /ConnectionString:"{YourAppHarborConnectionString}"

     /ModelFile:HackIt.dbschema

     /Properties:TargetDatabase={YourAppHarborDatabaseName EX:db1235}

I’ll explain a couple of the above command options.

/DeployToDatabase:-

This one is _key_. This tells vsdbcmd to only generate a change script, Viagra price, coupon, Herbal Viagra, and not to actually deploy the changes immediately. Until you feel comfortable with what sql the tool generates, Viagra australia, uk, us, usa, Viagra blogs, which is usually pretty darn good, you should not apply it immediately, Viagra dose. Allow the tool to generate the file for further inspection and you can execute it manually after, Buy Viagra Without Prescription. Viagra dosage,

/Script:Test.sql

This this is just the name of the file to dump the deployment changes.

/ModelFile:HackIt.dbschema

The path to the .dbschema we generated and modified above.

Review Change Script Generated.

After you’ve generated a change script file, order Viagra from United States pharmacy, Buy Viagra from canada, take a look at the sql just to make sure you’re happy with what it generates.

Take the app offline. (optional)

This one depends on the schema changes, Viagra class. Where can i find Viagra online, If the changes are serious enough, you can check in an App_Offline.htm file at the root of web project and do a “git push appharbor”, Viagra maximum dosage. Buy Viagra Without Prescription, This way, while making schema changes you don’t have to worry about the errors popping up on users. Is Viagra safe, Down side is your site becomes inoperable.

If you’ve never heard of the App_Offline.htm – I’d recommend reading up on it. http://weblogs.asp.net/scottgu/archive/2006/04/09/442332.aspx

Apply Change Script.

You have several options to actually apply the scripted changes.

1. Use vsdbcmd to deploy – Just turn the /DeployToDatabase:- to /DeployToDatabase:+ and allow vsdbcmd to apply the script right there, Viagra over the counter. Fast shipping Viagra,
2. Use SQL Management Studio.
   
   Make Sure you turn on SQLCMD Mode
   
    

Bring your site back online.

Now you can go re-name the App_Offline.htm to something like App_Offline.htm.disabled and push those changes back up to AppHarbor.

Other considerations.

• Consider a simple migrations framework (EX: DbUp) to get some initial data or things initialized, generic Viagra, Viagra australia, uk, us, usa, but be-ware that you’ll have to think a little harder about the “rollback” steps with this approach.

  
  

• Next you could take a look at an inquiry I made on the public support discussion list at AppHarbor hoping to push AppHarbor to implement this App_Offline.htm support (right into their admin site)
  
  http://support.appharbor.com/discussions/problems/373-deployment-feature-idea

  
  UPDATE: SPARE A VOTE OR TWO: http://feedback.appharbor.com/forums/95687-general/suggestions/1686365-add-feature-to-push-an-app-offline-htm-at-the-clic

One great benefit of to this approach is the ability for vsdbcmd to manage changes to an existing schema, rx free Viagra. Cheap Viagra,

Now if you want full support like refactorings such as table, column, Viagra treatment, Ordering Viagra online, etc renames. You will want to keep a full db project and use that to do a deployment.

Hope you find this useful, buy no prescription Viagra online. Taking Viagra, Happy Deployment!

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