C#DataRow注意的问题

using System;
using System.Data;
using System.Data.SqlClient;
 using System.Collections;
 using System.Text;
namespace AddingData {

///

/// Class1 的摘要说明。

 ///

class Class1 {

///

/// 应用程序的主入口点。

///

[STAThread]
static void Main(string[] args) {

SqlConnection thisConnection = new SqlConnection( "Server=(local); 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("#rowsbeforechange:{0}",thisDataSet.Tables["Customers"].Rows.Count);
DataRow thisRow = thisDataSet.Tables["Customers"].NewRow();
DataTable dtt = thisDataSet.Tables["Customers"]; DataColumn thisColumn = new DataColumn();
thisRow["CustomerID"] = "ZACZI";
thisRow["CompanyName"] = "Zachary Zithers Ltd";
dtt.Rows.Add(thisRow); DataRow thisrow = thisDataSet.Tables["Customers"].NewRow(); Console.WriteLine("# rows after change:{0}",thisDataSet.Tables["Customers"].Rows.Count);
 thisAdapter.Update(thisDataSet,"Customers");
//在这里要注意，这里会引发异常，有可能会出现主键约束的问题
DataTable dt = thisDataSet.Tables["Customers"];
DataRow rowTen = dt.Rows[9];
Object CustomerID = rowTen["CustomerID"];
Object CompanyName = rowTen["CompanyName"];
Console.WriteLine("before CusteomerID: {0} CompanyName: {1}",rowTen["CustomerID"],rowTen["CompanyName"]); //CompanyName = "aa";这里需要注意。因为不可以这样给他赋值,我试了几次，发现只能这样给里面赋值： rowTen["CompanyName"]="aa"); Console.WriteLine("changedCusteomerID:{0}CompanyName:{1}",rowTen["CustomerID"],rowTen["CompanyName"]="aa");
thisAdapter.Update(thisDataSet,"Customers"); thisConnection.Close(); Console.Write("Program finished ,press Enter/Return to continue"); Console.ReadLine();

}

}

}