String cstr = "User Id=snameche;Password=xxx;Host=localhost;Database=guce;Initial Schema=public";
                    using (var connection = new PgSqlConnection(cstr))
                    {
                        using (var contex = new guceEntities(connection))
                        {
                            contex.user_groups.Add(new user_groups { username = "Hawaii" , grp_id=10});
                            contex.SaveChanges();
                        }
                        using (var contex = new guceEntities(connection))
                        {
                            foreach (var destination in contex.user_groups)
                            {
                                Console.WriteLine(destination.username);
                            }
                        }
                    }

// Specify the provider name, server and database.
        string providerName = "Devart.Data.PostgreSql";
        string serverName = "localhost";
        string databaseName = "guce";
        string userID = "snameche";
        string password = "xxx";

        // Initialize the connection string builder for the
        // underlying provider.
        SqlConnectionStringBuilder sqlBuilder =
            new SqlConnectionStringBuilder();

        // Set the properties for the data source.
        sqlBuilder.DataSource = serverName;
        sqlBuilder.InitialCatalog = databaseName;
        sqlBuilder.IntegratedSecurity = true;
        sqlBuilder.UserID = userID;
        sqlBuilder.Password = password;

        // Build the SqlConnection connection string.
        string providerString = sqlBuilder.ToString();

        // Initialize the EntityConnectionStringBuilder.
        EntityConnectionStringBuilder entityBuilder =
            new EntityConnectionStringBuilder();

        //Set the provider name.
        entityBuilder.Provider = providerName;

        // Set the provider-specific connection string.
        entityBuilder.ProviderConnectionString = providerString;

        // Set the Metadata location.
        entityBuilder.Metadata = @"res://*/AdventureWorksModel.csdl|
                        res://*/AdventureWorksModel.ssdl|
                        res://*/AdventureWorksModel.msl";
        Console.WriteLine(entityBuilder.ToString());

        using (EntityConnection conn =
            new EntityConnection(entityBuilder.ToString()))
        {
            conn.Open();
            Console.WriteLine("Just testing the connection.");
            conn.Close();
        }