private void TableComboBox_DropDownOpened(object sender, EventArgs e)
 {
     var helper = new SqlDbHelper(ConnectionStringTextBox.Text);
     var provider = new SqlServerProvider(helper);
     var tables = provider.GetTableSchemas();
     TableComboBox.ItemsSource = tables.OrderBy(x => x.Name);
 }
        private void TableComboBox_DropDownOpened(object sender, EventArgs e)
        {
            if (_tables != null
                && _tables.Count() > 0
                && !String.IsNullOrEmpty(_connectionString)
                && !String.IsNullOrEmpty(ConnectionStringTextBox.Text)
                && _connectionString.Equals(ConnectionStringTextBox.Text))
            {
                TableComboBox.ItemsSource = _tables;
                return;
            }

            var helper = new SqlDbHelper(ConnectionStringTextBox.Text);
            var provider = new SqlServerProvider(helper);
            var tables = provider.GetTableSchemas();
            _tables = tables.OrderBy(x => x.Name);
            TableComboBox.ItemsSource = _tables;
        }