我也贴一个 MSSQL 的数据访问类

using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

namespace Tandy.Helper
{

    /// <summary>
    /// 
    /// 类名：DBHelper
    /// 
    /// 作用：用于处理对MSSQL数据库的增删改查操作
    /// 
    /// 作者：汤晓华 
    /// 
    /// 创建日期：2009年6月20日
    /// 
    /// </summary>
    [Serializable()]
    public class DBHelper
    {
        //连接字符串
        private static readonly string connectionString =
                            ConfigurationManager.ConnectionStrings["mssqlConnString"].ConnectionString;

        #region 方法
        /// <summary>
        /// 执行SQL语句或者存储过程的非查询操作
        /// </summary>
        /// <param name="cmdText">SQL语句或存储过程</param>
        /// <param name="cmdType">命令字符串类型</param>
        /// <param name="parameters">参数</param>
        /// <returns>INT 受影响行数</returns>
        public static int ExecuteNonQuery(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
        {
            //Sql命令处理对象
            SqlCommand cmd = new SqlCommand();

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                try
                {
                    //处理SqlCommand对象
                    PrepareCommand(cmd, connection, cmdText, cmdType, parameters);
                    //声明异步操作
                    IAsyncResult async = cmd.BeginExecuteNonQuery();

                    int val = cmd.EndExecuteNonQuery(async);

                    cmd.Dispose();

                    return val;
                }
                catch (SqlException ex)
                {

                    throw ex;
                }
            }
        }

        /// <summary>
        /// 返回数据集的首行首列
        /// </summary>
        /// <param name="cmdText">SQL语句或存储过程</param>
        /// <param name="cmdType">命令字符串类型</param>
        /// <param name="parameters">参数</param>
        /// <returns>返回首行首页</returns>
        public static object ExecuteScalar(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
        {
            //Sql命令处理对象
            SqlCommand cmd = new SqlCommand();

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                try
                {
                    //处理SqlCommand对象
                    PrepareCommand(cmd, connection, cmdText, cmdType, parameters);
                    object val = cmd.ExecuteScalar();
                    cmd.Dispose();
                    return val;
                }
                catch (SqlException ex)
                {

                    throw ex;
                }
            }
        }

        /// <summary>
        /// 获取数据流
        /// </summary>
        /// <param name="cmdText">SQL语句或存储过程</param>
        /// <param name="cmdType">命令字符串类型</param>
        /// <param name="parameters">参数</param>
        /// <returns>SqlDataReader对象</returns>
        public static SqlDataReader ExecuteReader(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
        {
            //Sql命令处理对象
            SqlCommand cmd = new SqlCommand();
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                try
                {
                    PrepareCommand(cmd, connection, cmdText, cmdType, parameters);
                    SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                    return rdr;
                }
                catch (SqlException ex)
                {
                    throw ex;
                }
            }

        }

        /// <summary>
        /// 获取数据集
        /// </summary>
        /// <param name="cmdText">SQL语句或存储过程</param>
        /// <param name="cmdType">命令字符串类型</param>
        /// <param name="parameters">参数</param>
        /// <returns>DataTable</returns>
        public static DataTable GetDataTable(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
        {
            SqlCommand cmd = new SqlCommand();

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                try
                {
                    PrepareCommand(cmd, connection, cmdText, cmdType, parameters);
                    DataTable table = new DataTable();
                    SqlDataAdapter sda = new SqlDataAdapter(cmd);
                    sda.Fill(table);
                    sda.Dispose();
                    cmd.Dispose();
                    return table;
                }
                catch (SqlException ex)
                {

                    throw ex;
                }
            }
        }



        /// <summary>
        /// 获取数据集
        /// </summary>
        /// <param name="cmdText">SQL语句或存储过程</param>
        /// <param name="cmdType">命令字符串类型</param>
        /// <param name="parameters">参数</param>
        /// <returns>DataTable</returns>
        public static SqlDataAdapter GetSqlDataAdapter(string cmdText, CommandType cmdType, params SqlParameter[] parameters)
        {
            SqlCommand cmd = new SqlCommand();

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                try
                {
                    PrepareCommand(cmd, connection, cmdText, cmdType, parameters);
                    SqlDataAdapter sda = new SqlDataAdapter(cmd);
                    return sda;
                }
                catch (SqlException ex)
                {

                    throw ex;
                }
            }
        }

        /// <summary>
        /// 处理SqlCommand对象
        /// </summary>
        /// <param name="cmdText">SQL语句或存储过程</param>
        /// <param name="cmdType">命令字符串类型</param>
        /// <param name="parameters">参数</param>
        /// <returns></returns>
        private static void PrepareCommand(SqlCommand cmd, SqlConnection connection, string cmdText, CommandType cmdType, SqlParameter[] parameters)
        {
            if (connection.State != ConnectionState.Open)
            {
                connection.Open();
            }
            cmd.Connection = connection;
            cmd.CommandText = cmdText;
            cmd.CommandType = cmdType;

            if (null != parameters)
            {
                cmd.Parameters.Clear();
                cmd.Parameters.AddRange(parameters);
            }
        }

        #endregion
    }
}