Lazy instantiation of SqlConnection

gistfile1.txt

// Ref: [mythz](https://groups.google.com/forum/#!topic/servicestack/bb95kGpDcEo)
using System;
using System.Configuration;
using System.Data;
using System.Data.Common;

namespace Clear2Pay.OTS.UTP.Data.Tests
{
    public class Database : IDisposable
    {
        private readonly string _connectionString;
        private IDbConnection _db;

        public Database()
        {
            _connectionString = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;
        }

        public Database(string connectionString)
        {
            _connectionString = connectionString;
        }

        public virtual IDbConnection Db
        {
            get
            {
                if (_db == null)
                {
                    var providerName = "System.Data.SqlClient";
                    var factory = DbProviderFactories.GetFactory(providerName);
                    _db = factory.CreateConnection();
                    if (_db == null)
                    {
                        throw new Exception("_db is null");
                    }
                    _db.ConnectionString = _connectionString;
                    _db.Open();
                    return _db;
                }
                return _db;
            }
        }

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