public static string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

<connectionStrings>  

<add name="ConnectionString" connectionString="Data Source=localhost;Persist Security Info=True;User ID=***;Password=***;Unicode=True"  

  providerName="System.Data.OracleClient" />  

</connectionStrings>  

public static string connectionString = ConfigurationSettings.AppSettings["ConnectionString"]; 

<add key="ConnectionString" value="server=localhost;database=***;uid=sa;pwd=***"></add>  

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <appSettings><!--2.--><add key="ConnectionString" value="***"></add></appSettings>

    <connectionStrings/><!--1.-->
    <system.web>
        <!-- 
            設(shè)置 compilation debug="true" 可將調(diào)試符號(hào)插入
            已編譯的頁(yè)面中。但由于這會(huì) 
            影響性能，因此只在開(kāi)發(fā)過(guò)程中將此值 
            設(shè)置為 true。
        -->
        <compilation debug="false"></compilation>
        <!--
            通過(guò) <authentication> 節(jié)可以配置 ASP.NET 用來(lái) 
            識(shí)別進(jìn)入用戶的
            安全身份驗(yàn)證模式。 
        -->
        <authentication mode="Windows" />
        <!--
            如果在執(zhí)行請(qǐng)求的過(guò)程中出現(xiàn)未處理的錯(cuò)誤，
            則通過(guò) <customErrors> 節(jié)可以配置相應(yīng)的處理步驟。具體說(shuō)來(lái)，
            開(kāi)發(fā)人員通過(guò)該節(jié)可以配置
            要顯示的 html 錯(cuò)誤頁(yè)
            以代替錯(cuò)誤堆棧跟蹤。
        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
    </system.web>
</configuration>

using System.Data;using Oracle.DataAccess.Client;  //注意添加Oracle的引用  ；SqlServer自帶    DataSet dataSet = new DataSet();List<ZHInfo> listzh = new List<ZHInfo>();string sql = "SELECT CODE,NAME,PHONE_NUMBER FROM ZHXX WHERE 1=1 AND ROWNUM<10 ";
using (OracleConnection oracleConnection = new OracleConnection(connectionString))
{
　　oracleConnection.Open();
　　OracleCommand selectCommand = new OracleCommand(sql, oracleConnection);
　　OracleDataAdapter oracleDataAdapter = new OracleDataAdapter(selectCommand);

　　oracleDataAdapter.Fill(dataSet);
}
if (dataSet.Tables.Count > 0 && dataSet.Tables[0] != null && dataSet.Tables[0].Rows.Count > 0)
{   //連接成功且返回?cái)?shù)據(jù)
　　foreach (DataRow dr in dataSet.Tables[0].Rows)
　　{
　　　　listzh.Add(new ZHInfo { Code = dr["Code"].ToString(), Name = dr["Name"].ToString(), PublicNumber = dr["Phone_Number"].ToString() });
　　}
}

public class ZHInfo
 {
    public string Code { get; set; }
    public string Name { get; set; }
    public string PublicNumber { get; set; }
}