Single Connection String with Multiple Entity Framework Models?

Question

At work we currently have a very large web application with a connection to a massive database. We have been using Entity Framework for a while now and to make things easier we

Answer 1

Add Default Construction in your Class

public class ItemContext : DbContext
{
    public DbSet<Item>Items get; set; }
    public DbSet<ItemDetail> ItemDetails { get; set; }

    public ItemContext ()
    {

        this.Database.Connection.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
    }
}

Answer 2

This is how I have implemented my solution to this problem:

namespace DBLibrary
{
    public enum Models
    {
        Model1,
        Model2    
    }

    public static class Database
    {
        public static string EntitiesConnectionString(Models model)
        {
            SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder(ConfigurationManager.ConnectionStrings["Default"].ConnectionString);

            builder["MultipleActiveResultSets"] = true;
            builder["Connect Timeout"] = 30;

            EntityConnectionStringBuilder entityBuilder = new EntityConnectionStringBuilder();
            entityBuilder.Provider = "System.Data.SqlClient";
            entityBuilder.ProviderConnectionString = builder.ConnectionString;

            switch (model)
            {
                case Models.Model1:
                    entityBuilder.Metadata = "res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl";
                    return entityBuilder.ToString();
                case Models.Model2:
                    entityBuilder.Metadata = "res://*/Model2.csdl|res://*/Model2.ssdl|res://*/Model2.msl";
                    return entityBuilder.ToString();
                default:
                    throw new Exception("Invalid model, no connection string defined");
            }
        }
    }
}

I still need to clean up the code and all but I think this give you a good idea on how this can be implemented. I would still be very interested if there are different and better ways of doing this.

Thanks!

Answer 3

I had the same problem. I have solved it by following way:

I have created two edmx file, but while creating second edmx file, i ignored the connection string to be save in config file. This way my config file will hold only one Connection string. Then i modified following lines in my connection string:

<add name="MyDbContext" connectionString="metadata=res://*/;provider=System.Data.SqlClient;provider connection string=&quot;data source=abc;initial catalog=mydb;persist security info=True;user id=myuser;password=password;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

Just replace "res://model1.csdl" with "res://*/" and it works like a charm.

You can specify this connection name in constructor of your dbcontext class like:

public MyDbContext() : base("name=NameOfYourConnectionString") //  Name of your connection string
{ }

Note: I am using Entity Framework 5.0.