SqlDataAdapter和SqlCommandBuilder删除数据

using System;
using System.Data;
using System.Data.SqlClient;

//SqlDataAdapter网站：http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldataadapter.aspx
//SqlCommandBuilder网站：http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommandbuilder.aspx

namespace Chapter13
{
class PersistDels
{
static void Main(string[] args)
{
// connection string
string connString = @"
server = .;
integrated security = true;
database = northwind
";

// query
string qry = @"
select
*
from
employees
where
country = 'UK'
";

// Create connection
SqlConnection conn = new SqlConnection(connString);

try
{
// create data adapter
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = new SqlCommand(qry, conn);

SqlCommandBuilder sqlCmdBder = new SqlCommandBuilder(da);

// create and fill dataset
DataSet ds = new DataSet();
da.Fill(ds, "employees");

// get data table reference
DataTable dt = ds.Tables["employees"];

// display rows
foreach (DataRow row in dt.Rows)
{
Console.WriteLine(
"{0} {1} {2}",
row["firstname"].ToString().PadRight(15),
row["lastname"].ToString().PadLeft(25),
row["city"]);
}

string filt = @"
firstname = 'Roy'
and
lastname = 'Beatty'
";
//
// delete employees
foreach (DataRow row in dt.Select(filt))
{
row.Delete();
}
//很重要的一步，把本地修改提交至至数据库。
da.Update(ds, "employees");
}
catch (Exception e)
{
Console.WriteLine("Error: " + e);
}
finally
{
// close connection
conn.Close();
}
}
}
}