ADO.NET 2.0 Dataset和Datatable 新功能新特性

<p style="FONT-SIZE: 10pt">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：

<p style="FONT-SIZE: 10pt">DataSet ds = new DataSet();

<p style="FONT-SIZE: 10pt"> 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"));

<p style="FONT-SIZE: 10pt"> Cursor.Current = Cursors.WaitCursor;

<p style="FONT-SIZE: 10pt"> DateTime datBegin = DateTime.Now;

<p style="FONT-SIZE: 10pt"> Random rand = new Random(); int i,intValue; DataRow dr;

<p style="FONT-SIZE: 10pt"> for (i = 1; i <= 500000; i++) { try { intValue = rand.Next();

<p style="FONT-SIZE: 10pt"> dr = ds.Tables[0].NewRow();

<p style="FONT-SIZE: 10pt"> dr["ID"] = intValue; dr["Value"] = intValue;

<p style="FONT-SIZE: 10pt"> ds.Tables[0].Rows.Add(dr); } catch { } }

<p style="FONT-SIZE: 10pt"> Cursor.Current = Cursors.Default;

<p style="FONT-SIZE: 10pt"> 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";

<p style="FONT-SIZE: 10pt"> DataSet ds = new DataSet(); SqlDataAdapter dadpt = new SqlDataAdapter("select from [order details]",connstr); dadpt.Fill(ds);

<p style="FONT-SIZE: 10pt"> 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);

<p style="FONT-SIZE: 10pt"> dt.WriteXml(@"c:\DataTable.xml",true); dt.WriteXmlSchema(@"c:\DataTableSchema.xml"); DataTable Read XMLStreamReader sr = new StreamReader(@"C:\DataTableSchema.xml");

<p style="FONT-SIZE: 10pt"> DataTable dt = new DataTable(); dt.ReadXmlSchema(sr);

<p style="FONT-SIZE: 10pt"> dt.ReadXml(new StreamReader(@"c:\dataTable.xml"));

<p style="FONT-SIZE: 10pt"> this.dataGridView1.DataSource = dt; DataTable Mergestring 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);

<p style="FONT-SIZE: 10pt"> SqlDataAdapter dadpt1 = new SqlDataAdapter("select from customers",connstr); DataTable dt1 = new DataTable("Customer1"); dadpt1.Fill(dt1);

<p style="FONT-SIZE: 10pt"> dt.Merge(dt1);

<p style="FONT-SIZE: 10pt"> this.dataGridView1.DataSource = dt; DataTable Load DataReaderstring 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();

<p style="FONT-SIZE: 10pt"> DataTable dt = new DataTable("Customer"); dt.Load(dr);

<p style="FONT-SIZE: 10pt"> this.dataGridView1.DataSource = dt;