初学者问题,关于ADO.NET数据库的RELATION
using System;
using System.Data;
using System.Data.SqlClient;
namespace ConsoleApplication4
{
/// <summary>
/// Class1 的摘要说明。
/// </summary>
class Class1
{
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main(string[] args)
{
//
SqlConnection thisConnection = new SqlConnection( @"Data Source =(local);Integrated Security=SSPI;" + "Initial Catalog = Test" );
thisConnection.Open();
SqlDataAdapter thisAdapter = new SqlDataAdapter( "select * from TestTable", thisConnection );
SqlCommandBuilder thisCommandBuilder = new SqlCommandBuilder( thisAdapter );
DataSet thisDataSet = new DataSet();
SqlDataAdapter custAdapter = new SqlDataAdapter( "select * from TestTable", thisConnection );
SqlDataAdapter oderAdapter = new SqlDataAdapter( "select * from TestTable2", thisConnection );
custAdapter.Fill( thisDataSet, "TestTalbe" );
oderAdapter.Fill( thisDataSet, "TestTalbe2" );
DataRelation custOrderRel = thisDataSet.Relations.Add( "CustOrders", thisDataSet.Tables["TestTable"].Columns["UserID"], thisDataSet.Tables["TestTable2"].Columns["UserID"] );
foreach( DataRow custRow in thisDataSet.Tables["TestTable"].Rows )
{
Console.WriteLine( "UserID:" + custRow["UserID"] + "\tUserName" + custRow["UserName"] );
foreach( DataRow orderRow in custRow.GetChildRows( custOrderRel ) )
{
Console.WriteLine( "UserID" + orderRow["UserID:"] + "Telephoe:" + orderRow["Telephone"] );
}
}
thisConnection.Close();
//
}
}
}
这个程序中的DataRelation custOrderRel = thisDataSet.Relations.Add( "CustOrders", thisDataSet.Tables["TestTable"].Columns["UserID"], thisDataSet.Tables["TestTable2"].Columns["UserID"] );
一句总是报
未处理的“System.NullReferenceException”类型的异常出现在 ConsoleApplication4.exe 中。
的错误 ,麻烦大侠们指点。先谢谢了