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ADO.NET 2.0 Dataset和Datatable 新功能新特性

发布时间:2020-07-16 04:31:14 所属栏目:asp.Net 来源:互联网
导读: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; d

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


<p style="FONT-SIZE: 10pt"> ds.RemotingFormat = SerializationFormat.Binary;


<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;

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