Transition from Entityspaces(Tiraggo) into Servicestack Ormlite

问题

at this moment we are migrating from Entityspaces(Tiraggo) into Servicestack Ormlite.

One point is the way to open and close the DBConnection.

I apologize for the comparission but it is useful for the question. In Tiraggo, inside my wep application, in the global.asax.cs I put this:

    protected void Application_Start(object sender, EventArgs e)
    {
        Tiraggo.Interfaces.tgProviderFactory.Factory = new Tiraggo.Loader.tgDataProviderFactory();
    }

In web.config exists the section for Tiraggo, the connectionstring and the ORM does the rest.

During the use of the classes we just do this:

User user = new User(); user.Name="some"; user.Comment = "some"; user.Save();

I dont open, close a DBConnection. It is transparent for the programmer. Just create the instance classes and use them.

I define a class, a repository and that's all. No DB definition or interaction. Everything happens in a webforms app, with the datalayer inside the same app.

When we are migrating to Servicestack ORMLite, I see the open of the DBConnection is too inside the globlal.asax.cs, but it references a Service no a class or repository.

   public class AppHost : AppHostBase
{
    public AppHost() : base("Hello ServiceStack", typeof(HelloService).Assembly) {}
    public override void Configure(Container container) {}
}

So my first question is: how can I use it if I dont have a Service (HelloService), I have just classes or repositories. So I cant use this technique for DBConnection my DB.

I also see that accesing the Db, I need a open connection. I try to do this:

            using (var Db = DbFactory.Conn.OpenDbConnection())
        {
            return Db.SingleById<Anio>(id);
        }

Later, I found a sample like I was looking for, the Pluralsight video ".NET Micro ORMs" Steve Mihcelotti, and he just open the connection, but never Close it, never use the "using" syntax.

So my 2 questions are:

1) Is there a way for open the DbFactory(dbConnection) like all the samples using servicestack ormlite, but without using a Services ( I dont use Services, I want to use Ormlite but just with classes and repositories) 2) Is there a way for connnect to the database in each trip to the class or repository without using the "using" syntax, or 3) the only way is the one showed in the Pluralsight video, ie. open the connection throw the using syntax in each Method (trip to the class)

I hope I was clear.

回答1:

The nice thing about IDbConnectionFactory is that it's a ThreadSafe Singleton which can be safely passed around and referenced as it doesn't hold any resources open itself (i.e. DB Connections).

A lazy pattern which provides a nice call-site API is the RepositoryBase class:

public abstract class RepositoryBase : IDisposable, IRepository
{
    public virtual IDbConnectionFactory DbFactory { get; set; }

    IDbConnection db;
    public virtual IDbConnection Db
    {
        get { return db ?? (db = DbFactory.OpenDbConnection()); }
    }

    public virtual void Dispose()
    {
        if (db != null)
            db.Dispose();
    }
}

This is the same pattern ServiceStack's Service class uses to provide a nice API that only gets opened when it's used in Services, e.g:

public class MyRepository : RepositoryBase
{
    public Foo GetFooById(int id)
    {
        return Db.SingleById<Foo>(id);
    }
}

Note: This pattern does expect that your dependencies will be disposed after use.

Another alternative is to leverage your IOC to inject an Open IDbConnection with a managed lifetime scope, e.g:

container.Register<IDbConnection>(c => 
    c.Resolve<IDbConnectionFactory>().OpenDbConnection())
    .ReusedWithin(ReuseScope.Request);

The life-cycle of the connection is then up to your preferred IOC.

Without Using an IOC

Whilst it's typically good practice to use an IOC to manage your Apps dependencies and provide loose-coupling, if you don't want to use an IOC you can also make DbFactory a static property, e.g:

public abstract class RepositoryBase : IDisposable
{
    public static IDbConnectionFactory DbFactory { get; set; }

    IDbConnection db;
    public virtual IDbConnection Db
    {
        get { return db ?? (db = DbFactory.OpenDbConnection()); }
    }

    public virtual void Dispose()
    {
        if (db != null)
            db.Dispose();
    }
}

Which you can just initialize directly on startup, e.g:

protected void Application_Start(object sender, EventArgs e)
{
    RepositoryBase.DbFactory = new OrmLiteConnectionFactory(
        connectionString, SqlServer.Provider);
}

Note: If you're not using an IOC then you want to make sure that instances of your repository classes (e.g. MyRepository) are disposed of after use.

来源：https://stackoverflow.com/questions/26290983/transition-from-entityspacestiraggo-into-servicestack-ormlite

标签

repository

servicestack

ormlite-servicestack