ADO.NET 2.0 Dataset和Datatable 新功能新特性

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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;

 

 

 

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