CODEWITHSUNDEEP
c#entity-frameworkconnectionconnection-string
duress
duress

Reputation: 77

Trying to connect to a database with ObjectContext, but fails

I'm playing around with POCOs in EF, working from a tiny basic setup to something more advanced. No interfaces of generics, just an easy point of entry. First of all I created an .edmx file, containing just one entity: Person, with 3 attributes. Id, FirstName and LastName.

With this I generated the database and added a few records into it manually. This database is called 'PocoTest' and the connection bit in my App.Config looks like:

<add name="PocoTestContainer" connectionString="metadata=res://*/PocoTest.csdl|res://*/PocoTest.ssdl|res://*/PocoTest.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=SEBASTIAAN-PC\SQLEXPRESS;Initial Catalog=PocoTest;Integrated Security=True;Pooling=False;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />

Firstly i created an Entity:

public class Person
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

Now I created a Context, inheriting from the ObjectContext:

public class PocoTestContext : ObjectContext
{
    private IObjectSet<Person> persons;

    public PocoTestContext()
        : base("name=PocoTestContainer", "PocoTestContainer")
    {
        ContextOptions.LazyLoadingEnabled = true;
        persons = CreateObjectSet<Person>();           
    }

    public IObjectSet<Person> Persons
    {
        get
        {
            return persons;
        }
    }
}

Nothing fancy here. Next thing is a repository:

public class PersonRepository
{
    PocoTestContext context;

    public PersonRepository()
    {
        context = new PocoTestContext();
    }

    public Person GetById(int id)
    {
        return context.Persons.Where(p => p.Id == id).FirstOrDefault();
    }

    public List<Person> GetAll()
    {
        List<Person> persons = null;

        try
        {
            persons = context.Persons.ToList();
        }
        catch(Exception e)
        {
            Console.WriteLine(e.InnerException);
        }
        return persons;
    }

    public void Add(Person entity)
    {
        context.Persons.AddObject(entity);
    }

    public void Save()
    {
        context.SaveChanges();
    }
}

Now all of this compiles fine, but I can't seem to connect to the database, since i don't get any results returned. When I check the connectionstate in the PocoTestContext constructor the connection isn't established. Now I'm guessing something is wrong with the way I use the connectionstring. I stole this approach from another project in which I did use a generated repository.

Any help would be greatly appreciated!

Upvotes: 1

Views: 563

Answers (2)

duress
duress

Reputation: 77

I've come up with the solution, the edmx file held a reference to 'PersonSet', I manually changed this to 'Person'. Now I get the expected results.

Upvotes: 1

Ladislav Mrnka
Ladislav Mrnka

Reputation: 364349

Connection is not established in the constructor. It is established when it is needed and closed once it is not needed.

Upvotes: 1

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