Examples of common ADO.net objects

Demo of commonly used ADO.net objects

This routine demonstrates the usage of OleDbConnection, OleDbCommand, cmd. Parameters, OleDbDataReader, OleDbDataAdapter, DataSet, and other objects. This is the result of several days of research.

Using System;
Using System. Collections. Generic;
Using System. ComponentModel;
Using System. Data;
Using System. Drawing;
Using System. Linq;
Using System. Text;
Using System. Windows. Forms;
Using System. Data. OleDb;
Using System. IO;
Using System. Diagnostics;

Namespace WindowsFormsApplication5
{
Public partial class Form1: Form
{
Public Form1 ()
{
InitializeComponent ();
}

* ****** Void button#click (object sender, EventArgs e) //
{

OleDbConnection cn = new OleDbConnection ("Provider = Microsoft. jet. OLEDB.4.0; Data Source = "+ Application. startupPath + "\ flList. mdb "+"; Persist Security Info = True ");
Cn. Open ();

OleDbCommand cmd = new OleDbCommand ();
Cmd. Connection = cn;
Cmd. CommandText = "insert into list (linktxt, url, shopname, bz, banner, html) values (?,?,?,?,?,?) ";
Cmd. Parameters. Add ("linktxt", OleDbType. VarChar );
Cmd. Parameters ["linktxt"]. Value = "的 ";
Cmd. Parameters. Add ("url", OleDbType. VarChar );
Cmd. Parameters ["url"]. Value = "http://www.hackpig.cn ";
Cmd. Parameters. Add ("shopname", OleDbType. VarChar );
Cmd. Parameters ["shopname"]. Value = "yipinxiang ";
Cmd. Parameters. Add ("BZ", oledbtype. varchar );
Cmd. Parameters ["BZ"]. value = "yipinxiang ";
Cmd. Parameters. Add ("banner", oledbtype. varchar );
Cmd. Parameters ["banner"]. value = "banner ";
Cmd. Parameters. Add ("html", oledbtype. varchar );

Filestream FS = new filestream (application. startuppath + "\ html.txt", filemode. Open, fileaccess. Read );
Byte [] buffer = new byte [fs. Length];
Fs. Read (buffer, 0, buffer. Length );
Fs. Close ();
Cmd. Parameters ["html"]. Value = Encoding. Default. GetString (buffer );

Cmd. Parameters. Add ("babysum", OleDbType. VarChar );
Cmd. Parameters ["babysum"]. Value = 333;
Cmd. Parameters. Add ("sellerxy", OleDbType. VarChar );
Cmd. Parameters ["sellerxy"]. Value = 35;
Cmd. Parameters. Add ("mjxy", OleDbType. VarChar );
Cmd. Parameters ["mjxy"]. value = 11;
Cmd. Parameters. Add ("shopdate", oledbtype. varchar );
Cmd. Parameters ["shopdate"]. value = "1988-11-13 ";
Cmd. Parameters. Add ("scrq", oledbtype. varchar );
Cmd. Parameters ["scrq"]. value = 41;
Cmd. Parameters. Add ("service", oledbtype. varchar );
Cmd. Parameters ["service"]. value = true;
Cmd. Parameters. Add ("wherefrom", oledbtype. varchar );
Cmd. Parameters ["wherefrom"]. value = "Wuhan, China ";
Cmd. Parameters. Add ("modulehtml", oledbtype. varchar );
Cmd. Parameters ["modulehtml"]. value = "modulehtml ";

Cmd. executenonquery ();
CN. Close ();
}

P rivate void button2_click (Object sender, eventargs E)
{

Oledbconnection Cn = new oledbconnection ("provider = Microsoft. jet. oledb.4.0; Data Source = "+ application. startuppath + "\ fllist. mdb "+"; persist Security info = true ");
CN. open ();

Oledbcommand cmd = new oledbcommand ();
Cmd. Connection = cn;
Cmd. commandtext = "select * from List ";

// Oledbdatareader the data reader is read-only
Oledbdatareader reader = cmd. executereader ();

While (reader. Read ())
{
// Debug. writeline (Reader [1]. tostring ());
Richtextbox1.text + = reader [0]. tostring ();
Richtextbox1.text + = "\ n ";
Richtextbox1.text + = reader [1]. tostring ();
Richtextbox1.text + = "\ n ";
RichTextBox1.Text + = reader [2]. ToString ();
RichTextBox1.Text + = "\ n ";
RichTextBox1.Text + = reader [3]. ToString ();
RichTextBox1.Text + = "\ n ";

}
Reader. Close ();

}

P rivate void button3_Click (object sender, EventArgs e)
{// DataBindings
Oledbconnection Cn = new oledbconnection ("provider = Microsoft. jet. oledb.4.0; Data Source = "+ application. startuppath + "\ fllist. mdb "+"; persist Security info = true ");
CN. open ();
Oledbcommand cmd = new oledbcommand ();
Cmd. Connection = cn;

Oledbdataadapter adapter1 = new oledbdataadapter ("select top 1 * From list", CN );
// Adapter1.selectcommand = "select * from List ";
Dataset dataset1 = new dataset ();

Adapter1.fill (dataset1, "list ");
Textbox1.databindings. Add ("text", dataset1, "list. BZ ");

 

}

P rivate void button4_click (Object sender, eventargs E)
{
// Read dataset data
Oledbconnection Cn = new oledbconnection ("provider = Microsoft. jet. oledb.4.0; Data Source = "+ application. startuppath + "\ fllist. mdb "+"; persist Security info = true ");
CN. open ();
OleDbCommand cmd = new OleDbCommand ();
Cmd. Connection = cn;

OleDbDataAdapter adapter1 = new OleDbDataAdapter ("select top 1 * from list", cn );
// Adapter1.SelectCommand = "select * from list ";
DataSet dataSet1 = new DataSet ();

Adapter1.Fill (dataSet1, "list ");
Debug. WriteLine (dataSet1.Tables [0]. Rows. Count );
String str1 = null;
DataTable table = dataSet1.Tables [0];
Foreach (DataRow row in table. Rows)
{
Foreach (DataColumn column in table. Columns)
{
Str1 + = row [column];
// Debug. WriteLine (str1 );
Str1 + = "\ n ";
}
Str1 + = "\ n ";
}
Richtextbox1.text = str1;

}
}
}