給你個例子[.NET中三層構架開發實例 - 用戶注冊系統]

數據庫基類
using System;
using System.Data;
using System.Data.SqlClient;
namespace HaiSky.HtJob
{
    /// <summary>
    /// DbClass 的摘要說明。
    /// </summary>
    public class DbClass
    {
        private string connectionString;
        protected SqlConnection Connection;
        public DbClass(string newConnectionString)
        {
            connectionString = newConnectionString;
            Connection = new SqlConnection(connectionString);
        }
        public string ConnectionString
        {
            get
            {
                return connectionString;
            }
        }
        private SqlCommand BuildQueryCommand(string storedProcName,IDataParameter[] parameters)
        {
            SqlCommand command = new SqlCommand(storedProcName,Connection);
            command.CommandType = CommandType.StoredProcedure;