• asp.net 数据库连接的方法


     
    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



    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

    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:\BegASPNET\Northwind.mdb"是指明数据源的位置,他的标准形式是"Data Source=MyDrive:MyPath\MyFile.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

    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

    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

    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

    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:

    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)

    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;
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  • 原文地址:https://www.cnblogs.com/csn0721/p/1488910.html
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