Sub LoadCommandList()
Dim objConn As New Odbc.OdbcConnection
Dim objCmd As New Odbc.OdbcCommand
Dim objDataReader As Odbc.OdbcDataReader
CommandList.Items.Clear()
objConn.ConnectionString = "Driver={Microsoft Access Driver (*.mdb)};Dbq=" & Application.StartupPath & "database.mdb"
Debug.Print(Application.StartupPath & "database.mdb")
objConn.Open()'连接数据库
objCmd.Connection = objConn
objCmd.CommandText = "select * from Commands"
objDataReader = objCmd.ExecuteReader()'执行SQL语句
While objDataReader.Read()'读数据，以下和数据库连接无关
CommandList.Items.Add(objDataReader.GetString(0) & "," & objDataReader.GetString(1))
End While
objConn.Close()
End Sub
二
Asp.net连接SQL Server2000数据库例程详解:
<%@ Import Namespace="System.Data" %>
<%@ Import NameSpace="System.Data.SqlClient" %>
<script laguage="VB" runat="server">
sub page_load(sender as Object,e as EventArgs)
Dim myConnection As SqlConnection
Dim myCommand As SqlCommand
Dim ds as DataSet
'1.连接数据库
myConnection = New SqlConnection( "server=localhost;database=Pubs;uid=ueytjdf;pwd=doekdf" )
myConnection.Open()
la1.text="Connection Opened!"
'2.建立一个新表
myCommand = New SqlCommand( "CREATE TABLE [test] ([id] [int] IDENTITY (1, 1) NOT NULL ,[name] [char] (10) COLLATE Chinese_PRC_CI_AS NULL ,[sex] [char] (10) COLLATE Chinese_PRC_CI_AS NULL )", myConnection )
myCommand.ExecuteNonQuery()
la2.text="New table created!"
'2 添加纪录
myCommand = New SqlCommand( "Insert into [test] (name,sex) values( '黄志文','男' )", myConnection )
myCommand.ExecuteNonQuery()
la3.text="New Record Inserted!"
'3 更新数据
myCommand = New SqlCommand( "UPDATE [test] SET name='Smith' where name='李明'", myConnection )
myCommand.ExecuteNonQuery()
la4.text="Record Updated!"
'4 删除数据
myCommand = New SqlCommand( "delete from [test] where name='Smith'", myConnection )
myCommand.ExecuteNonQuery()
la5.text="Record Deleted!"
'5 用DataGrid显示数据
myCommand = New SqlCommand( "select * from [test]", myConnection )
MyDataGrid.DataSource=myCommand.ExecuteReader()
MyDataGrid.DataBind()
end sub
</script>
<html>
<body>
<asp:label id="la1" runat="server" /><br>
<asp:label id="la2" runat="server" /><br>
<asp:label id="la3" runat="server" /><br>
<asp:label id="la4" runat="server" /><br>
<asp:label id="la5" runat="server" /><br>
<ASP:DataGrid id="MyDataGrid" runat="server"
BorderColor="black"
BorderWidth="1"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
Font-Name="Verdana"
Font-Size="10pt"
HeaderStyle-BackColor="#aaaadd"
AlternatingItemStyle-BackColor="#eeeeee"
>
</asp:DataGrid>
</body>
</html>
----------------------------------------------------------------------------------------------------
ASP.net连接access数据库例程
<%@ Import Namespace="System.Data" %>
<%@ Import NameSpace="System.Data.OleDb" %>
<script laguage="VB" runat="server">
Dim myConnection As OleDbConnection
Dim myCommand As OleDbCommand
sub page_load(sender as Object,e as EventArgs)
'1.连接数据库
dim dbname as string
dbname=server.mappath("authors.mdb")
myConnection = New OleDbConnection( "PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA Source="&dbname )
myConnection.Open()
la1.text="Connection Opened!"
'2.添加记录
myCommand = New OleDbCommand( "Insert INTO Authors(Authors,country) Values('Simson','usa')", myConnection )
myCommand.ExecuteNonQuery()
la2.text="New Record Inserted!"
'3 更新数据(Access)
myCommand = New OleDbCommand( "UPDATE Authors SET Authors='Bennett' WHERE Authors = 'Simson'", myConnection )
myCommand.ExecuteNonQuery()
la3.text="Record Updated!"
'4 删除数据（access）
myCommand = New OleDbCommand( "DELETE FROM Authors WHERE Authors = 'David'", myConnection )
myCommand.ExecuteNonQuery()
la4.text="Record Deleted!"
'5 使用DateGrid显示数据
myCommand = New OleDbCommand( "select * FROM Authors", myConnection )
MyDataGrid.DataSource=myCommand.Executereader()
MyDataGrid.DataBind()
end sub
</script>
<html>
<body>
<asp:label id="la1" runat="server" /><br>
<asp:label id="la2" runat="server" /><br>
<asp:label id="la3" runat="server" /><br>
<asp:label id="la4" runat="server" /><br>
<ASP:DataGrid id="MyDataGrid" runat="server"
BorderColor="black"
BorderWidth="1"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
Font-Name="Verdana"
Font-Size="10pt"
HeaderStyle-BackColor="#aaaadd"
AlternatingItemStyle-BackColor="#eeeeee"
>
</asp:DataGrid>
</body>
</html>
1.C#连接连接Access
[复制此代码]CODE:
using System.Data;
using System.Data.OleDb;
..
string strConnection="Provider=Microsoft.Jet.OleDb.4.0;";
strConnection+=@"Data Source=C:BegASPNETNorthwind.mdb";
OleDbConnection objConnection=new OleDbConnection(strConnection);
..
objConnection.Open();
objConnection.Close();
解释:
连接Access数据库需要导入额外的命名空间,所以有了最前面的两条using命令,这是必不可少的!
strConnection这个变量里存放的是连接数据库所需要的连接字符串,他指定了要使用的数据提供者和要使用的数据源.
"Provider=Microsoft.Jet.OleDb.4.0;"是指数据提供者,这里使用的是Microsoft Jet引擎,也就是Access中的数据引擎,asp.net就是靠这个和Access的数据库连接的.
"Data Source=C:BegASPNETNorthwind.mdb"是指明数据源的位置,他的标准形式是"Data Source=MyDrive:MyPathMyFile.MDB".
PS:
1."+="后面的"@"符号是防止将后面字符串中的""解析为转义字符.
2.如果要连接的数据库文件和当前文件在同一个目录下,还可以使用如下的方法连接:
strConnection+="Data Source=";
strConnection+=MapPath("Northwind.mdb");
这样就可以省得你写一大堆东西了!
3.要注意连接字符串中的参数之间要用分号来分隔.
"OleDbConnection objConnection=new OleDbConnection(strConnection);"这一句是利用定义好的连接字符串来建立了一个链接对象,以后对数据库的操作我们都要和这个对象打交道.
"objConnection.Open();"这用来打开连接.至此,与Access数据库的连接完成.
2.C#连接SQL Server
[复制此代码]CODE:
using System.Data;
using System.Data.SqlClient;
..
string strConnection="user id=sa;password=;";
strConnection+="initial catalog=Northwind;Server=YourSQLServer;";
strConnection+="Connect Timeout=30";
SqlConnection objConnection=new SqlConnection(strConnection);
..
objConnection.Open();
objConnection.Close();
解释:
连接SQL Server数据库的机制与连接Access的机制没有什么太大的区别,只是改变了Connection对象和连接字符串中的不同参数.
首先,连接SQL Server使用的命名空间不是"System.Data.OleDb",而是"System.Data.SqlClient".
其次就是他的连接字符串了,我们一个一个参数来介绍(注意:参数间用分号分隔):
"user id=sa":连接数据库的验证用户名为sa.他还有一个别名"uid",所以这句我们还可以写成"uid=sa".
"password=":连接数据库的验证密码为空.他的别名为"pwd",所以我们可以写为"pwd=".
这里注意,你的SQL Server必须已经设置了需要用户名和密码来登录,否则不能用这样的方式来登录.如果你的SQL Server设置为Windows登录,那么在这里就不需要使用"user id"和"password"这样的方式来登录,而需要使用"Trusted_Connection=SSPI"来进行登录.
"initial catalog=Northwind":使用的数据源为"Northwind"这个数据库.他的别名为"Database",本句可以写成"Database=Northwind".
"Server=YourSQLServer":使用名为"YourSQLServer"的服务器.他的别名为"Data Source","Address","Addr".如果使用的是本地数据库且定义了实例名,则可以写为"Server=(local)实例名";如果是远程服务器,则将"(local)"替换为远程服务器的名称或IP地址.
"Connect Timeout=30":连接超时时间为30秒.
在这里,建立连接对象用的构造函数为:SqlConnection.
3.C#连接Oracle
[复制此代码]CODE:
using System.Data.OracleClient;
using System.Data;
//在窗体上添加一个按钮，叫Button1，双击Button1，输入以下代码
private void Button1_Click(object sender, System.EventArgs e)
{
string ConnectionString="Data Source=sky;user=system;password=manager;";//写连接串
OracleConnection conn=new OracleConnection(ConnectionString);//创建一个新连接
try
{
conn.Open();
OracleCommand cmd=conn.CreateCommand();
cmd.CommandText="select * from MyTable";//在这儿写sql语句
OracleDataReader odr=cmd.ExecuteReader();//创建一个OracleDateReader对象
while(odr.Read())//读取数据，如果odr.Read()返回为false的话，就说明到记录集的尾部了
{
Response.Write(odr.GetOracleString(1).ToString());//输出字段1，这个数是字段索引，具体怎么使用字段名还有待研究
}
odr.Close();
}
catch(Exception ee)
{
Response.Write(ee.Message); //如果有错误，输出错误信息
}
finally
{
conn.Close(); //关闭连接
}
}
4.C#连接MySQL
[复制此代码]CODE:
using MySQLDriverCS;
// 建立数据库连接
MySQLConnection DBConn;
DBConn = new MySQLConnection(new MySQLConnectionString("localhost","mysql","root","",3306).AsString);
DBConn.Open();
// 执行查询语句
MySQLCommand DBComm;
DBComm = new MySQLCommand("select Host,User from user",DBConn);
// 读取数据
MySQLDataReader DBReader = DBComm.ExecuteReaderEx();
// 显示数据
try
{
while (DBReader.Read())
{
Console.WriteLine("Host = {0} and User = {1}", DBReader.GetString(0),DBReader.GetString(1));
}
}
finally
{
DBReader.Close();
DBConn.Close();
}
//关闭数据库连接
DBConn.Close();
5.C#连接IBM DB2
[复制此代码]CODE:
OleDbConnection1.Open();
//打开数据库连接
OleDbDataAdapter1.Fill(dataSet1,"Address");
//将得来的数据填入dataSet
DataGrid1.DataBind();
//绑定数据
OleDbConnection1.Close();
//关闭连接
//增加数据库数据
在Web Form上新增对应字段数量个数的TextBox，及一个button，为该按键增加Click响应事件代码如下：
[复制此代码]CODE:
this.OleDbInsertCommand1.CommandText = "INSERTsintosADDRESS(NAME,
EMAIL, AGE, ADDRESS) VALUES
('"+TextBox1.Text+"','"+TextBox2.Text+"','"+TextBox3.Text+"','"+TextBox4.Text+"')";
OleDbInsertCommand1.Connection.Open();
//打开连接
OleDbInsertCommand1.ExecuteNonQuery();
//执行该SQL语句
OleDbInsertCommand1.Connection.Close();
//关闭连接
6.C#连接SyBase
(OleDb)
[复制此代码]CODE:
Provider=Sybase.ASEOLEDBProvider.2;Initial Catalog=数据库名;User ID=用户名;Data Source=数据源;Extended Properties="";Server Name=ip地址;Network Protocol=Winsock;Server Port Address=5000
