private void btnExecuteSQLAsDataTable_Click(object sender, EventArgs e)
        {
            try
            {
                lblTitle.Text = "Execute SQL to DataTable : GET ALL COUNTRIES";
                string query = QueryBase.GetAllFrom(eTables.country);

                DataTable dataTable = null;
                Task.Factory.StartNew(() =>
                {
                    dataTable = sqlHandler.ExecuteSQL(query);
                }).Wait();

                dgvResult.DataSource = dataTable;
            }
            catch (Exception ex)
            {
                DisplayError(ex.Message);
            }
        }
        private void btnExecuteAsListUsingSQLQuery_Click(object sender, EventArgs e)
        {
            try
            {
                lblTitle.Text = "Execute As List Using SQL Query : GET LIST OF CITIES";

                string query = QueryBase.GetAllFrom(eTables.city);

                List <City> lstCities = null;
                Task.Factory.StartNew(() =>
                {
                    lstCities = sqlHandler.ExecuteAsListUsingQuery <City>(query);
                }).Wait();

                dgvResult.DataSource = lstCities;
            }
            catch (Exception ex)
            {
                DisplayError(ex.Message);
            }
        }