EDMX and DbContext? Database First

Question

Rowan I am trying to whip up a quick app with an existing DB.

Is there a path to create an EDMX file and then create my DbContext with DbSets so that I can continue to work with all othe greatness of CTP4 stuff?

Model:

	public class IssueTrackerDB : DbContext
	{
		public DbSet<ITIssue> ITIssues { get; set; }

Controller:

			IssueTrackerDB DB = new IssueTrackerDB();
			var itIssues = DB.ITIssues;

I have tried this and am getting this error

base {System.Data.EntityException} = {"Schema specified is not valid. Errors: \r\nThe types in the assembly 'IssueTracker.MVC3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' cannot be loaded because the assembly contains the EdmSchemaAttribute, and the closure of types is being loaded by name.  Loading by both name and attribute is not allowed.

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Thanks, Terrence

 

 

Answer 1

Hi Terrence,

It is possible but a little messy in CTP4;

class Program
{
  static void Main(string[] args)
  {
    var builder = new ModelBuilder();
    builder.RegisterEdmx("<path to EDMX file>");
    var model = builder.CreateModel();

    using(var db = new IssueTrackerDB(model))
    {
      // Data access code
    }

  }
}

public class IssueTrackerDB : DbContext
{
  public IssueTrackerDB(DbModel model)
    : base(model)
  { }

  public DbSet<ITIssue> ITIssues { get; set; }
}

This will be a lot cleaner in CTP5, in fact we will ship T4 templates that will generate the context for you off the EDMX file.

~Rowan

Answer 2

Thanks Rowan, can't wait until the CTP5.  I noticed in one of the PDC demos that the guy downloaded it with NuGet. 

 

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Thanks, Terrence

Answer 3

Hi Terrence,

Yes CTP4 is available via NuGet and CTP5 will be too :)

~Rowan