用Visual C＃来增加数据记录（１）

2024-07-21 02:22:33

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　　在本篇文章中，我们将介绍visual c#对数据库的一个基本操作，即：如何往数据库中添加记录。我们将通过一些数据库操作的例子，来具体说明一下。为了更清楚的说明这个问题，在选用数据库方面采用了二种当前比较典型的数据库，其一是本地数据库--access 2000，另外一个是远程数据库--sql server 7.0。首先介绍如何用visual c#来添加access 2000数据库的记录。

一．用visual c#来添加access 2000数据库的记录
（一）.程序设计和运行的环境设置：
（1）视窗2000服务器版
（2）microsoft data acess component 2.6 以上版本 ( mdac 2.6 )
（3）本文程序使用的数据库的介绍：

程序中使用的数据库名称为sample.mdb，在此数据库中有一张数据表books。此数据表的结构如下：
字段名称字段类型代表意思bookid数字序号booktitle文本书籍名称bookauthor文本书籍作者bookprice数字价格bookstock数字书架号
（二）.程序设计难点和应该注意的问题：
如何正确的往数据库中添加记录是本文要讨论的一个重点和难点，下面就是解决这一问题的具体思路：
（1）创建并打开一个 oledbconnection对象。
（2）创建一个插入一条记录的sql语句。
（3）创建一个oledbcommand对象。
（4）通过此oledbcommand对象完成对插入一条记录到数据库的操作。
以下是在程序中实现的具体语句：
string strconn = " provider = microsoft.jet.oledb.4.0 ; data source = sample.mdb " ;
oledbconnection myconn = new oledbconnection ( strconn ) ;
myconn.open ( ) ;
string strinsert = " insert into books ( bookid , booktitle , bookauthor , bookprice , bookstock ) values ( " ;
strinsert += t_bookid.text + ", '" ;
strinsert += t_booktitle.text + "', '" ;
strinsert += t_bookauthor.text + "', " ;
strinsert += t_bookprice.text + ", " ;
strinsert += t_bookstock.text + ")" ;
oledbcommand inst = new oledbcommand ( strinsert , myconn ) ;
inst.executenonquery ( ) ;
myconn.close ( ) ;

（三）.用visual c#来插入记录的程序源代码( add.cs )和执行后的界面：
下图是add.cs编译后的执行界面：

add.cs源程序代码：
using system ;
using system.drawing ;
using system.componentmodel ;
using system.windows.forms ;
using system.data.oledb ;
using system.data ;
//导入程序中使用到的名称空间
public class dataadd : form {
private button lastrec ;
private button nextrec ;
private button previousrec ;
private button firstrec ;
private container components ;
private label title ;
private button t_new ;
private button save ;
private textbox t_bookstock ;
private textbox t_bookprice ;
private textbox t_bookauthor ;
private textbox t_booktitle ;
private textbox t_bookid ;
private label l_bookstock ;
private label l_bookprice ;
private label l_bookauthor ;
private label l_booktitle ;
private label l_bookid ;
private dataset mydataset ;
private bindingmanagerbase mybind ;
//定义在程序中要使用的组件
public dataadd ( ) {
//连接到一个数据库
getconnected ( ) ;
// 对窗体中所需要的内容进行初始化
initializecomponent ( );
}
//释放程序使用过的所以资源
public override void dispose ( ) {
base.dispose ( ) ;
components.dispose ( ) ;
}
public static void main ( ) {
application.run ( new dataadd ( ) ) ;
}
public void getconnected ( )
{
try{
//创建一个 oledbconnection对象
string strcon = " provider = microsoft.jet.oledb.4.0 ; data source = sample.mdb" ;
oledbconnection myconn = new oledbconnection ( strcon ) ;
string strcom = " select * from books " ;
//创建一个 dataset
mydataset = new dataset ( ) ;
myconn.open ( ) ;
//用 oledbdataadapter 得到一个数据集
oledbdataadapter mycommand = new oledbdataadapter ( strcom , myconn ) ;
//把dataset绑定books数据表
mycommand.fill ( mydataset , "books" ) ;
//关闭此oledbconnection
myconn.close ( ) ;
}
catch ( exception e )
{
messagebox.show ( "连接错误! " + e.tostring ( ) , "错误" ) ;
}
}
private void initializecomponent ( )
{
components = new system.componentmodel.container ( ) ;
nextrec = new button ( ) ;
lastrec = new button ( ) ;
previousrec = new button ( ) ;
firstrec = new button ( ) ;
t_bookprice = new textbox ( ) ;
l_booktitle = new label ( ) ;
l_bookprice = new label ( ) ;
l_bookauthor = new label ( ) ;
t_bookid = new textbox ( ) ;
save = new button ( ) ;
title = new label ( ) ;
t_bookauthor = new textbox ( ) ;
t_booktitle = new textbox ( ) ;
t_new = new button ( ) ;
l_bookstock = new label ( ) ;
t_bookstock = new textbox ( ) ;
l_bookid = new label ( ) ;
//以下是对数据浏览的四个按钮进行初始化
firstrec.location = new system.drawing.point ( 65 , 312 ) ;
firstrec.forecolor = system.drawing.color.black ;
firstrec.size = new system.drawing.size ( 40 , 24 ) ;
firstrec.font = new system.drawing.font("仿宋", 8f );
firstrec.text = "首记录";
firstrec.click += new system.eventhandler(gofirst);
previousrec.location = new system.drawing.point ( 135 , 312 ) ;
previousrec.forecolor = system.drawing.color.black ;
previousrec.size = new system.drawing.size(40, 24) ;
previousrec.font = new system.drawing.font ( "仿宋" , 8f ) ;
previousrec.text = "上一条" ;
previousrec.click += new system.eventhandler ( goprevious ) ;
nextrec.location = new system.drawing.point ( 205 , 312 );
nextrec.forecolor = system.drawing.color.black ;
nextrec.size = new system.drawing.size ( 40 , 24 ) ;
nextrec.font = new system.drawing.font ( "仿宋" , 8f ) ;
nextrec.text = "下一条" ;
nextrec.click += new system.eventhandler ( gonext );
lastrec.location = new system.drawing.point ( 275 , 312 ) ;
lastrec.forecolor = system.drawing.color.black ;
lastrec.size = new system.drawing.size ( 40 , 24 ) ;
lastrec.font = new system.drawing.font ( "仿宋" , 8f ) ;
lastrec.text = "尾记录" ;
lastrec.click += new system.eventhandler ( golast ) ;
//以下是对显示标签进行初始化
l_bookid.location = new system.drawing.point ( 24 , 56 ) ;
l_bookid.text = "书本序号：" ;
l_bookid.size = new system.drawing.size ( 112, 20 ) ;
l_bookid.font = new system.drawing.font ( "仿宋" , 10f ) ;
l_bookid.textalign = system.drawing.contentalignment.middlecenter ;
l_booktitle.location = new system.drawing.point ( 24 , 108 ) ;
l_booktitle.text = "书名：";
l_booktitle.size = new system.drawing.size ( 112 , 20 ) ;
l_booktitle.font = new system.drawing.font ( "仿宋" , 10f ) ;
l_booktitle.textalign = system.drawing.contentalignment.middlecenter ;
l_bookprice.location = new system.drawing.point ( 24 , 212 ) ;
l_bookprice.text = "价格：" ;
l_bookprice.size = new system.drawing.size ( 112 , 20 ) ;
l_bookprice.font = new system.drawing.font ( "仿宋" , 10f ) ;
l_bookprice.textalign = system.drawing.contentalignment.middlecenter ;
l_bookstock.location = new system.drawing.point ( 24 , 264 ) ;
l_bookstock.text = "书架号：" ;
l_bookstock.size = new system.drawing.size ( 112 , 20 ) ;
l_bookstock.font = new system.drawing.font ( "仿宋" , 10f ) ;
l_bookstock.tabindex = 16 ;
l_bookstock.textalign = system.drawing.contentalignment.middlecenter ;
l_bookauthor.location = new system.drawing.point ( 24 , 160 ) ;
l_bookauthor.text = "作者：" ;
l_bookauthor.size = new system.drawing.size ( 112 , 20 ) ;
l_bookauthor.font = new system.drawing.font ( "仿宋" , 10f ) ;
l_bookauthor.textalign = system.drawing.contentalignment.middlecenter ;
title.location = new system.drawing.point ( 32 , 16 ) ;
title.text = "利用vsiual c#来增加数据记录！" ;
title.size = new system.drawing.size ( 336 , 24 ) ;
title.forecolor = system.drawing.color.green ;
title.font = new system.drawing.font ( "仿宋" , 14f , system.drawing.fontstyle.bold ) ;
//以下是对为显示数据记录而设定的标签和文本框进行初始化，并把记录绑定在不同的绑定到文本框"text"属性上
t_bookid.location = new system.drawing.point ( 184 , 56 ) ;
t_bookid.size = new system.drawing.size ( 80 , 20 ) ;
t_bookid.databindings.add ( "text" , mydataset , "books.bookid" ) ;
t_bookstock.location = new system.drawing.point ( 184 , 264 ) ;
t_bookstock.size = new system.drawing.size ( 80 , 20 ) ;
t_bookstock.databindings.add ( "text" , mydataset , "books.bookstock" ) ;
t_booktitle.location = new system.drawing.point ( 184 , 108 ) ;
t_booktitle.size = new system.drawing.size ( 176 , 20 ) ;
t_booktitle.databindings.add( "text" , mydataset , "books.booktitle" ) ;
t_bookprice.location = new system.drawing.point ( 184 , 212 ) ;
t_bookprice.size = new system.drawing.size ( 80 , 20 ) ;
t_bookprice.databindings.add ( "text" , mydataset , "books.bookprice" ) ;
t_bookauthor.location = new system.drawing.point ( 184 , 160 ) ;
t_bookauthor.size = new system.drawing.size ( 128 , 20 ) ;
t_bookauthor.databindings.add ( "text" , mydataset , "books.bookauthor" ) ;
t_new.location = new system.drawing.point ( 62 , 354 ) ;
t_new.size = new system.drawing.size ( 96 , 32 ) ;
t_new.text = "新建记录" ;
t_new.click += new system.eventhandler ( t_newclick ) ;
save.location = new system.drawing.point ( 222 , 354 ) ;
save.size = new system.drawing.size ( 96 , 32 ) ;
save.tabindex = 4 ;
save.text = "保存记录" ;
save.click += new system.eventhandler ( saveclick ) ;
this.text = "利用vsiual c#来增加数据记录的程序窗口！" ;
this.autoscalebasesize = new system.drawing.size ( 5 , 13 ) ;
this.formborderstyle = formborderstyle.fixed3d ;
this.clientsize = new system.drawing.size ( 390 , 400 ) ;
//在窗体中加入下列组件
this.controls.add ( lastrec ) ;
this.controls.add ( nextrec ) ;
this.controls.add ( previousrec ) ;
this.controls.add ( firstrec ) ;
this.controls.add ( title ) ;
this.controls.add ( t_new ) ;
this.controls.add ( save ) ;
this.controls.add ( t_bookstock ) ;
this.controls.add ( t_bookprice ) ;
this.controls.add ( t_bookauthor ) ;
this.controls.add ( t_booktitle ) ;
this.controls.add ( t_bookid ) ;
this.controls.add ( l_bookstock ) ;
this.controls.add ( l_bookprice ) ;
this.controls.add ( l_bookauthor ) ;
this.controls.add ( l_booktitle ) ;
this.controls.add ( l_bookid ) ;
//把对象dataset和"books"数据表绑定到此mybind对象
mybind= this.bindingcontext [ mydataset , "books" ] ;
}
protected void saveclick ( object sender , system.eventargs e )
{
try
{
//判断所有字段是否添完，添完则执行，反之弹出提示
if ( t_bookid.text != "" && t_booktitle.text != "" && t_bookauthor.text != "" && t_bookprice.text != "" && t_bookstock.text != "" )
{
string strconn = " provider = microsoft.jet.oledb.4.0 ; data source = sample.mdb " ;
oledbconnection myconn = new oledbconnection ( strconn ) ;
myconn.open ( ) ;
string strinsert = " insert into books ( bookid , booktitle , bookauthor , bookprice , bookstock ) values ( " ;
strinsert += t_bookid.text + ", '" ;
strinsert += t_booktitle.text + "', '" ;
strinsert += t_bookauthor.text + "', " ;
strinsert += t_bookprice.text + ", " ;
strinsert += t_bookstock.text + ")" ;
oledbcommand inst = new oledbcommand ( strinsert , myconn ) ;
inst.executenonquery ( ) ;
myconn.close ( ) ;
}
else
{
messagebox.show ( "必须填满所有字段值！" , "错误！" ) ;
}
}
catch ( exception ed )
{
messagebox.show ( "保存数据记录发生 " + ed.tostring ( ) , "错误！" ) ;
}
}
protected void t_newclick ( object sender , system.eventargs e )
{
t_bookid.text = "" ;
t_booktitle.text = "" ;
t_bookauthor.text = "" ;
t_bookprice.text = "" ;
t_bookstock.text = "" ;
}
//按钮"尾记录"对象事件程序
protected void golast ( object sender , system.eventargs e )
{
mybind.position = mybind.count - 1 ;
}

//按钮"下一条"对象事件程序
protected void gonext ( object sender , system.eventargs e )
{
if ( mybind.position == mybind.count -1 )
messagebox.show ( "已经到了最后一条记录！" ) ;
else
mybind.position += 1 ;
}
//按钮"上一条"对象事件程序
protected void goprevious ( object sender , system.eventargs e )
{
if ( mybind.position == 0 )
messagebox.show ( "已经到了第一条记录！" ) ;
else
mybind.position -= 1 ;
}
//按钮"首记录"对象事件程序
protected void gofirst ( object sender , system.eventargs e )
{
mybind.position = 0 ;
}
}

成功编译上面代码，就可以往access 2000数据库里面插入记录了。

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