四．插入數據記錄： </P><P>　　對數據庫進行插入記錄操作和刪除記錄操作基本的思路是一致的，就是通過ADO.NET首先插入數據記錄到數據庫，然后對"DataSet"對象進行必要的修改。下列代碼就是以Access 2000數據庫為模型修改當前記錄的代碼： </P><P>protected void Update_record ( object sender , System.EventArgs e )
{

int i = myBind.Position ;

try{

file://連接到一個數據庫

string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb " ;

OleDbConnection myConn = new OleDbConnection ( strCon ) ;

myConn.Open ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . BeginEdit ( ) ;

file://從數據庫中修改指定記錄

string strUpdt = " UPDATE person SET xm = '"

+ t_xm.Text + "' , xb = '"

+ t_xb.Text + "' , nl = "

+ t_nl.Text + " , zip = "

+ t_books.Text + " WHERE id = " + t_id.Text ;

OleDbCommand myCommand = new OleDbCommand ( strUpdt , myConn ) ;

myCommand.ExecuteNonQuery ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . EndEdit ( ) ;

myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;

myConn.Close ( ) ;

}

catch ( Exception ed )

{

MessageBox.Show ( "修改指定記錄錯誤： " + ed.ToString ( ) , "錯誤！" ) ;

}

myBind.Position = i ;

} </P><P>　　由于對Sql Server 2000數據記錄修改操作和Access 2000數據記錄修改操作的差異只在于不同的數據鏈接，具體的代碼可以參考"刪除數據記錄"中的代碼，在這里就不提供了。



五．插入數據記錄：



　　和前面二種操作在思路是一致的，就是通過ADO.NET首先插入數據記錄到數據庫，然后對"DataSet"對象進行必要的修改。下列代碼就是以Access 2000數據庫為模型插入一條數據記錄的代碼



protected void Insert_record ( object sender , System.EventArgs e )

{

try

{

file://判斷所有字段是否添完，添完則執行，反之彈出提示

if ( t_id.Text != "" && t_xm.Text != "" && t_xb.Text != "" && t_nl.Text != "" && t_books.Text != "" )

{

string myConn1 = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb" ;

OleDbConnection myConn = new OleDbConnection ( myConn1 ) ;

myConn.Open ( ) ;

string strInsert = " INSERT INTO person ( id , xm , xb , nl , zip ) VALUES ( " ;

strInsert += t_id.Text + ", '" ;

strInsert += t_xm.Text + "', '" ;

strInsert += t_xb.Text + "', " ;

strInsert += t_nl.Text + ", " ;

strInsert += t_books.Text + ")" ;

OleDbCommand inst = new OleDbCommand ( strInsert , myConn ) ;

inst.ExecuteNonQuery ( ) ;

myConn.Close ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . BeginEdit ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . EndEdit ( ) ;

myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;

}

else

{

MessageBox.Show ( "必須填滿所有字段值！" , "錯誤！" ) ;

}

}

catch ( Exception ed )

{

MessageBox.Show ( "保存數據記錄發生 " + ed.ToString ( ) , "錯誤！" ) ;

}

}



　　同樣對Sql Server 2000數據庫進行插入記錄操作和Access 2000數據庫插入記錄操作的差異也只在于不同的數據鏈接，具體的代碼可以參考"刪除數據記錄"中的代碼，在這里就不提供了。

　　六．Visual C＃數據庫編程的完成源代碼和程序運行的主界面：



　　掌握了上面要點，編寫一個完整的數據庫編程的程序就顯得非常容易了，下面是Visual C＃進行數據庫編程的完整代碼（Data01.cs），此代碼是以Access 2000數據庫為模型設計的，具體如下：



using System ;

using System.Drawing ;

using System.ComponentModel ;

using System.Windows.Forms ;

using System.Data.OleDb ;

using System.Data ;



public class Data : Form

{

private System.ComponentModel.Container components = null ;

private Button lastrec ;

private Button nextrec ;

private Button previousrec ;

private Button firstrec ;

private TextBox t_books ;

private TextBox t_nl ;

private ComboBox t_xb ;

private TextBox t_xm ;

private TextBox t_id ;

private Label l_books ;

private Label l_nl ;

private Label l_xb ;

private Label l_xm ;

private Label l_id ;

private Label label1 ;

private DataSet myDataSet ;

private Button button1 ;

private Button button2 ;

private Button button3 ;

private Button button4 ;

private BindingManagerBase myBind ;



public Data ( )

{

file://連接到一個數據庫

GetConnected ( ) ;

// 對窗體中所需要的內容進行初始化

InitializeComponent ( ) ;

}

file://清除在程序中使用過的資源

protected override void Dispose( bool disposing )

{

if( disposing )

{

if ( components != null )

{

components.Dispose ( ) ;

}

}

base.Dispose( disposing ) ;

}

public static void Main ( )

{

Application.Run ( new Data ( ) ) ;

}

public void GetConnected ( )

{

try

{

file://創建一個 OleDbConnection

string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb" ;

OleDbConnection myConn = new OleDbConnection ( strCon ) ;

string strCom = " SELECT * FROM person " ;

file://創建一個 DataSet

myDataSet = new DataSet ( ) ;



myConn.Open ( ) ;

file://用 OleDbDataAdapter 得到一個數據集

OleDbDataAdapter myCommand = new OleDbDataAdapter ( strCom , myConn ) ;

file://把Dataset綁定books數據表

myCommand.Fill ( myDataSet , "person" ) ;

file://關閉此OleDbConnection

myConn.Close ( ) ;

}

catch ( Exception e )

{

MessageBox.Show ( "連接錯誤! " + e.ToString ( ) , "錯誤" ) ;

}

}

private void InitializeComponent ( )

{



file://添加控件，略



this.Name = "Data" ;

this.Text = "Visual C＃的數據庫編程！" ;

this.ResumeLayout(false) ;

myBind = this.BindingContext [ myDataSet , "person" ] ;

}

protected void New_record ( object sender , System.EventArgs e )

{

t_id.Text = ( myBind.Count + 1 ).ToString ( ) ;

t_xm.Text = "" ;

t_xb.Text = "" ;

t_nl.Text = "" ;

t_books.Text = "" ;

}

protected void Insert_record ( object sender , System.EventArgs e )

{

try

{

file://判斷所有字段是否添完，添完則執行，反之彈出提示

if ( t_id.Text != "" && t_xm.Text != "" && t_xb.Text != "" && t_nl.Text != "" && t_books.Text != "" )

{

string myConn1 = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb" ;

OleDbConnection myConn = new OleDbConnection ( myConn1 ) ;

myConn.Open ( ) ;

string strInsert = " INSERT INTO person ( id , xm , xb , nl , zip ) VALUES ( " ;

strInsert += t_id.Text + ", '" ;

strInsert += t_xm.Text + "', '" ;

strInsert += t_xb.Text + "', " ;

strInsert += t_nl.Text + ", " ;

strInsert += t_books.Text + ")" ;

OleDbCommand inst = new OleDbCommand ( strInsert , myConn ) ;

inst.ExecuteNonQuery ( ) ;

myConn.Close ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . BeginEdit ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . EndEdit ( ) ;

myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;

}

else

{

MessageBox.Show ( "必須填滿所有字段值！" , "錯誤！" ) ;

}

}

catch ( Exception ed )

{

MessageBox.Show ( "保存數據記錄發生 " + ed.ToString ( ) , "錯誤！" ) ;

}

}

protected void Update_record ( object sender , System.EventArgs e )

{

int i = myBind.Position ;

try{

file://連接到一個數據庫

string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb " ;

OleDbConnection myConn = new OleDbConnection ( strCon ) ;

myConn.Open ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . BeginEdit ( ) ;

file://從數據庫中修改指定記錄

string strUpdt = " UPDATE person SET xm = '"

+ t_xm.Text + "' , xb = '"

+ t_xb.Text + "' , nl = "

+ t_nl.Text + " , zip = "

+ t_books.Text + " WHERE id = " + t_id.Text ;

OleDbCommand myCommand = new OleDbCommand ( strUpdt , myConn ) ;

myCommand.ExecuteNonQuery ( ) ;

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . EndEdit ( ) ;

myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;

myConn.Close ( ) ;

}

catch ( Exception ed )

{

MessageBox.Show ( "修改指定記錄錯誤： " + ed.ToString ( ) , "錯誤！" ) ;

}

myBind.Position = i ;

}



protected void Delete_record ( object sender , System.EventArgs e )

{

DialogResult r = MessageBox.Show ( "是否刪除當前記錄！" , "刪除當前記錄！" , MessageBoxButtons.YesNo , MessageBoxIcon.Question ) ;

int ss = ( int ) r ;

　 if ( ss == 6 ) // 按動"確定"按鈕

{

try{

file://連接到一個數據庫

string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb " ;

OleDbConnection myConn = new OleDbConnection ( strCon ) ;

myConn.Open ( ) ;

string strDele = "DELETE FROM person WHERE id= " + t_id.Text ;

OleDbCommand myCommand = new OleDbCommand ( strDele , myConn ) ;

file://從數據庫中刪除指定記錄

myCommand.ExecuteNonQuery ( ) ;

file://從DataSet中刪除指定記錄

myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . Delete ( ) ;

myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;

myConn.Close ( ) ;

}

catch ( Exception ed )

{

MessageBox.Show ( "刪除記錄錯誤信息： " + ed.ToString ( ) , "錯誤！" ) ;

}

}

}

file://按鈕"尾記錄"對象事件程序

protected void GoLast ( object sender , System.EventArgs e )

{

myBind.Position = myBind.Count - 1 ;

}



file://按鈕"下一條"對象事件程序

protected void GoNext ( object sender , System.EventArgs e )

{

if ( myBind.Position == myBind.Count -1 )

MessageBox.Show ( "已經到了最后一條記錄！", "信息提示！" , MessageBoxButtons.OK , MessageBoxIcon.Information ) ;

else

myBind.Position += 1 ;

}

file://按鈕"上一條"對象事件程序

protected void GoPrevious ( object sender , System.EventArgs e )

{

if ( myBind.Position == 0 )

MessageBox.Show ( "已經到了第一條記錄！" , "信息提示！" , MessageBoxButtons.OK , MessageBoxIcon.Information ) ;

else

myBind.Position -= 1 ;

}

file://按鈕"首記錄"對象事件程序

protected void GoFirst ( object sender , System.EventArgs e )

{

myBind.Position = 0 ;

}

}





　　對于以Sql Server 2000數據庫為模型的程序代碼，只要把Data01.cs中的數據鏈接，即：

string myConn1 = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb" ;



　　改換成：

string strCon = "Provider = SQLOLEDB.1 ; Persist Security Info = False ; User ID = sa ; Initial Catalog = data1 ; Data Source = server1 " ;



　　注釋：此數據鏈接代表的意思是：打開Sql server數據庫，服務器名稱為server1,數據庫為data1

就可以得到Visual C＃針對Sql Server 2000數據庫為模板編程的完成源程序代碼了。所以本文就不再提供了。



　　七．總結：



　　數據庫編程始終是程序編程內容中的一個重點和難點。而以上介紹的這些操作又是數據庫編程中最為基本，也是最為重要的內容。那些復雜的編程無非是以上這些處理的若干個疊加。