ADO.NET 2.0 Dataset和Datatable 新功能新特性

1.新的索引引擎更快的执行效率
   下面这段代码在2003中需要157秒，在2005中只要11秒就可以完成：

DataSet ds  
 = 
   
 new 
  DataSet();

            ds.Tables.Add( 
 " 
 BigTable 
 " 
 );
            ds.Tables[ 
 0 
 ].Columns.Add( 
 " 
 ID 
 " 
 , Type.GetType( 
 " 
 System.Int32 
 " 
 ));
            ds.Tables[ 
 0 
 ].Columns[ 
 " 
 ID 
 " 
 ].Unique  
 = 
   
 true 
 ;
            ds.Tables[ 
 0 
 ].Columns.Add( 
 " 
 Value 
 " 
 , Type.GetType( 
 " 
 System.Int32 
 " 
 ));

            Cursor.Current  
 = 
  Cursors.WaitCursor;

            DateTime datBegin  
 = 
  DateTime.Now;

            Random rand  
 = 
   
 new 
  Random();
             
 int 
  i, intValue;
            DataRow dr;

             
 for 
  (i  
 = 
   
 1 
 ; i  
 <= 
   
 500000 
 ; i 
 ++ 
 )
             
 
 
 {
                try
                
{
                    intValue = rand.Next();

                    dr = ds.Tables[0].NewRow();

                    dr["ID"] = intValue;
                    dr["Value"] = intValue;

                    ds.Tables[0].Rows.Add(dr);
                }
                catch 
{ }
            } 
 

            Cursor.Current  
 = 
  Cursors.Default;

            MessageBox.Show( 
 " 
 Elapsed Time:  
 " 
   
 + 
  (DateTime.Now  
 - 
  datBegin).Seconds.ToString());
            MessageBox.Show( 
 " 
 count =  
 " 
   
 + 
  ds.Tables[ 
 0 
 ].Rows.Count.ToString());
2.Dataset可以序列化为二进制文件 

  
   string 
  connstr  
 = 
   
 " 
 server=(local);database=northwind;integrated security=true;async=true 
 " 
 ;

            DataSet ds   = 
   
 new 
  DataSet();
            SqlDataAdapter dadpt   = 
   
 new 
  SqlDataAdapter( 
 " 
 select * from [order details] 
 " 
 , connstr);
            dadpt.Fill(ds);

            BinaryFormatter bf   = 
   
 new 
  BinaryFormatter();
            FileStream fs   = 
   
 new 
  FileStream( 
 @" 
 c:/xml1.txt 
 " 
 ,FileMode.OpenOrCreate);

            ds.RemotingFormat = SerializationFormat.Binary;   

            bf.Serialize(fs,ds);     3.更独立的Datatable 

  DataTable Write XML 
  
   string   connstr  
 = 
   
 " 
 server=(local);database=northwind;integrated security=true;async=true 
 " 
 ;
            SqlDataAdapter dadpt   =    
 new 
  SqlDataAdapter( 
 " 
 select * from [order details] 
 " 
 , connstr);
            DataTable dt   =    
 new 
  DataTable( 
 " 
 Customer 
 " 
 );
            dadpt.Fill(dt);

            dt.WriteXml(  @"  c:/DataTable.xml 
 " 
 , 
 true 
 );
            dt.WriteXmlSchema(  @"  c:/DataTableSchema.xml 
 " 
 );   DataTable Read XML 

  
 StreamReader sr   =     new 
  StreamReader( 
 @" 
 C:/DataTableSchema.xml 
 " 
 );

            DataTable dt   =     new 
  DataTable();
            dt.ReadXmlSchema(sr);

            dt.ReadXml(  new   StreamReader(  @" 
 c:/dataTable.xml 
 " 
 ));

              this  .dataGridView1.DataSource   = 
  dt;    DataTable Merge 

  
   string   connstr   =    
 " 
 server=(local);database=northwind;integrated security=true;async=true 
 " 
 ;
            SqlDataAdapter dadpt   =     new   SqlDataAdapter( 
 " 
 select * from customers 
 " 
 , connstr);
            DataTable dt   =     new   DataTable( 
 " 
 Customer 
 " 
 );
            dadpt.Fill(dt);

            SqlDataAdapter dadpt1   =     new   SqlDataAdapter( 
 " 
 select * from customers 
 " 
 , connstr);
            DataTable dt1   =     new   DataTable( 
 " 
 Customer1 
 " 
 );
            dadpt1.Fill(dt1);

            dt.Merge(dt1);

              this  .dataGridView1.DataSource   =   dt;  DataTable Load DataReader 

  
   string   connstr   =     " 
 server=(local);database=northwind;integrated security=true;async=true 
 " 
 ;
            SqlConnection conn   =     new   SqlConnection(connstr);
            conn.Open();
            SqlCommand cmd   =     new   SqlCommand(  " 
 select * from [order details] 
 " 
 , conn);
            SqlDataReader dr   =   cmd.ExecuteReader();

            DataTable dt   =     new   DataTable(  " 
 Customer 
 " 
 );
            dt.Load(dr);

              this  .dataGridView1.DataSource   =   dt;