ADO Database C#

using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Text;
class Program {
    static void Main(string[] args) {
        SqlConnection thisConnection = new SqlConnection(
             @"Server=(local)\sqlexpress;Integrated Security=True;" +
             "Database=northwind");
        SqlDataAdapter thisAdapter = new SqlDataAdapter("SELECT CustomerID, CompanyName FROM Customers", thisConnection);
        SqlCommandBuilder thisBuilder = new SqlCommandBuilder(thisAdapter);
        DataSet thisDataSet = new DataSet();
        thisAdapter.Fill(thisDataSet, "Customers");
        Console.WriteLine("# rows before change: {0}",thisDataSet.Tables["Customers"].Rows.Count);
        DataColumn[] keys = new DataColumn[1];
        keys[0] = thisDataSet.Tables["Customers"].Columns["CustomerID"];
        thisDataSet.Tables["Customers"].PrimaryKey = keys;
        DataRow findRow = thisDataSet.Tables["Customers"].Rows.Find("ZACZI");
        if (findRow != null) {
            findRow.Delete();
            thisAdapter.Update(thisDataSet, "Customers");
        }
        Console.WriteLine("# rows after change: {0}",
             thisDataSet.Tables["Customers"].Rows.Count);
        thisConnection.Close();
    }
}