我的第一个SqlHelper.cs

这个也借鉴了几个版本的一些代码。我没有写对存储过程的操作，因为我写不好存储过程。。。。。这个写完之后，我连测试都没测过。就当做给大家的反面教材吧！

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

namespace Model
{
    class SqlHelper
    {
        #region 通用方法
        // 数据连接池
        private SqlConnection con;
        /// <summary>
        /// 返回数据库连接字符串
        /// </summary>
        /// <returns></returns>
        public static String GetSqlConnection()
        {
            // 连接字符串
            String conn = "";
            return conn;
        }

        #region 数据库连接和关闭
        /// <summary>
        /// 打开连接池
        /// </summary>
        private void Open()
        {
            // 打开连接池
            if (con == null)
            {
                //这里不仅需要using System.Configuration;还要在引用目录里添加
                con = new SqlConnection(GetSqlConnection());
                con.Open();
            }
        }
        /// <summary>
        /// 关闭连接池
        /// </summary>
        public void Close()
        {
            if (con != null)
                con.Close();
        }
        /// <summary>
        /// 释放连接池
        /// </summary>
        public void Dispose()
        {
            // 确定连接已关闭
            if (con != null)
            {
                con.Dispose();
                con = null;
            }
        }
        #endregion

        #endregion
         
        #region 执行sql字符串

        #region 执行不带参数的SQL语句
        /// <summary>
        /// 执行不带参数的SQL语句
        /// </summary>
        /// <param name="Sqlstr"></param>
        /// <returns></returns>
        public static int ExecuteSql(String Sqlstr)
        {
            String ConnStr = GetSqlConnection();
            int re = 0;
            try
            {
                using (SqlConnection conn = new SqlConnection(ConnStr))
                {
                    SqlCommand cmd = new SqlCommand();
                    cmd.Connection = conn;
                    cmd.CommandText = Sqlstr;
                    conn.Open();
                    re = cmd.ExecuteNonQuery();
                    conn.Close();
                    
                }
            }
            catch(Exception e)
            {
                throw e;
            }
            return re;
        }
        #endregion

        #region 执行带参数的SQL语句
        /// <summary>
        /// 执行带参数的SQL语句
        /// </summary>
        /// <param name="Sqlstr">SQL语句</param>
        /// <param name="param">参数对象数组</param>
        /// <returns></returns>
        public static int ExecuteSql(String Sqlstr, SqlParameter[] Params)
        {
            String ConnStr = GetSqlConnection();
            int re = 0;
            try
            {
                using (SqlConnection conn = new SqlConnection(ConnStr))
                {
                    SqlCommand cmd = new SqlCommand();
                    cmd.Connection = conn;
                    cmd.CommandText = Sqlstr;
                    cmd.Parameters.AddRange(Params);
                    conn.Open();
                    re = cmd.ExecuteNonQuery();
                    conn.Close();

                }
            }
            catch(Exception e)
            {
                throw e;
            }
            return re;
        }
        #endregion

        #region 执行SQL语句并返回数据表(无参数)
        /// <summary>
        /// 执行SQL语句并返回数据表(无参数)
        /// </summary>
        /// <param name="Sqlstr">SQL语句</param>
        /// <returns></returns>
        public static DataSet ExecuteDt(String Sqlstr)
        {
            String ConnStr = GetSqlConnection();
            DataSet dt = new DataSet();
            try
            {
                using (SqlConnection conn = new SqlConnection(ConnStr))
                {
                    SqlDataAdapter da = new SqlDataAdapter(Sqlstr, conn);
                    conn.Open();
                    da.Fill(dt);
                    conn.Close();
                }
            }
            catch (Exception e)
            {
                throw e;
            }
            return dt;
        }

        #endregion

        #region 执行SQL语句并返回数据表(有参数)
        /// <summary>
        /// 执行SQL语句并返回数据表(有参数)
        /// </summary>
        /// <param name="Sqlstr">SQL语句</param>
        /// <returns></returns>
        public static DataSet ExecuteDt(String Sqlstr, SqlParameter[] Params)
        {
            String ConnStr = GetSqlConnection();
            DataSet dt = new DataSet();
            try
            {
                using (SqlConnection conn = new SqlConnection(ConnStr))
                {
                    SqlCommand cmd = new SqlCommand();
                    cmd.Connection = conn;
                    cmd.CommandText = Sqlstr;
                    cmd.Parameters.AddRange(Params);

                    SqlDataAdapter da = new SqlDataAdapter(cmd);
                    conn.Open();
                    da.Fill(dt);
                    conn.Close();

                }
            }
            catch(Exception e)
            {
                throw e;
            }
            return dt;
        }
        #endregion

 
        #endregion

    }
}

欢迎来喷。如果喷，请轻喷。。。。。。。