asp.net 通用的连接数据库实例代码
view code
<%@ page language="c#" autoeventwireup="true" codefile="default.aspx.cs" inherits="_default" %>
<center>
<h2><font face="宋体">访问数据库的通用代码实例</font>
</h2>
</center>
<body>
<form id="form1" runat="server">
<div>
<font face="宋体">
<p align="center">1.请输入相应数据库连接字符串</p>
<p align="center">
<asp:textbox id="connstrtextbox" runat="server" width="600"></asp:textbox>
</p>
<p align="center">2.请输入相应sql查询命令语句</p>
<p align="center">
<asp:textbox id="sqltexttextbox" runat="server" width="600"></asp:textbox>
</p>
<p align="center">3.请选择所连接的数据库类型</p>
<p align="center">
<asp:dropdownlist id="dbdropdownlist" runat="server" width="204px">
<asp:listitem selected="true">access</asp:listitem>
<asp:listitem>sqlserver</asp:listitem>
<asp:listitem>oracle</asp:listitem>
<asp:listitem>db2</asp:listitem>
</asp:dropdownlist>
</p>
<p align="center">
<asp:button id="button1" runat="server" onclick="button1_click" text="通用数据库连接代码测试" />
</p>
<p align="center">
<asp:label id="lblmessage" runat="server" font-bold="true" forecolor="red"></asp:label>
</p>
</form>
</font>
</div>
asp.net页面
using system;
using system.configuration;
using system.data;
using system.linq;
using system.web;
using system.web.security;
using system.web.ui;
using system.web.ui.htmlcontrols;
using system.web.ui.webcontrols;
using system.web.ui.webcontrols.webparts;
using system.xml.linq;
public partial class _default : system.web.ui.page
{
protected void page_load(object sender, eventargs e)
{
//通用数据库连接代码，这里以连接access数据库为测试示例
if (!ispostback)
{
connstrtextbox.text = "provider=microsoft.jet.oledb.4.0; data source=" + server.mappath("user.mdb");
sqltexttextbox.text = "select count(*) from info where name='小顾'";
lblmessage.text = "";
}
}
protected void button1_click(object sender, eventargs e)
{
//定义数据库连接字符串
string myconnectionstring = this.connstrtextbox.text;
//定义查询操作的sql语句
string mysql = this.sqltexttextbox.text;
//定义所要连接的数据库类型为access
string mytype = this.dbdropdownlist.selectedvalue;
system.data.idbconnection myconnection = null;
// 根据数据库类型，创建相应的 connection 对象
switch (mytype)
{
//选择的数据库类型为“sqlserver”，创建sqlconnection类数据库连接对象
case "sqlserver":
myconnection = new system.data.sqlclient.sqlconnection(myconnectionstring);
break;
case "oracle":
myconnection = new system.data.oracleclient.oracleconnection(myconnectionstring);
break;
//选择的数据库类型为“access”，创建oledbconnection类数据库连接对象
case "access":
myconnection = new system.data.oledb.oledbconnection(myconnectionstring);
break;
//选择的数据库类型为“db2”，创建oledbconnection类数据库连接对象
case "db2":
myconnection = new system.data.odbc.odbcconnection(myconnectionstring);
break;
default:
myconnection = new system.data.oledb.oledbconnection(myconnectionstring);
break;
}
execute(myconnection, mysql);
}
public void execute(system.data.idbconnection myconnection, string strquery)
{
//使用 createcommand() 方法生成 command 对象
system.data.idbcommand mycommand = myconnection.createcommand();
//执行定义的sql查询语句
mycommand.commandtext = strquery;
try
{
//打开数据库连接
myconnection.open();
//定义查询的结果信息
string myinfo = "测试连接成功！符合查询要求的记录共有：" + mycommand.executescalar().tostring() + "条！";
//输出查询结果信息
lblmessage.text = myinfo;
}
catch (exception ex)
{
//输出错误异常
response.write(ex.tostring());
}
finally
{
//关闭数据库连接
myconnection.close();
}
}
}
本段程序的核心代码为
//选择的数据库类型为“sqlserver”，创建sqlconnection类数据库连接对象
case "sqlserver":
myconnection = new system.data.sqlclient.sqlconnection(myconnectionstring);
break;
case "oracle":
myconnection = new system.data.oracleclient.oracleconnection(myconnectionstring);
break;
//选择的数据库类型为“access”，创建oledbconnection类数据库连接对象
case "access":
myconnection = new system.data.oledb.oledbconnection(myconnectionstring);
break;
//选择的数据库类型为“db2”，创建oledbconnection类数据库连接对象
case "db2":
myconnection = new system.data.odbc.odbcconnection(myconnectionstring);
break;
default:
myconnection = new system.data.oledb.oledbconnection(myconnectionstring);
break;
如果你要其它连接我们还可以增加一些连接代码哦。