SQL数据连接

 public string m_sMessage = "";    //返回信息

 private string m_sConnectionString = "";    //连接字符串

 private string m_sServerName = "";    //服务器
 private string m_sDataBase = "";    //数据库
 private string m_sUserId = "";        //帐号
private string m_sPassword = "";    //密码

 public SqlConnection m_conObj = new SqlConnection();    //连接对象

 this.m_sConnectionString = "data source=" + this.m_sServerName + ";" +

                "initial catalog=" + this.m_sDataBase + ";" +
                "user id=" + this.m_sUserId + ";" +
                "password=" + this.m_sPassword + "";

或者

 this.m_sConnectionString = "server=" + this.m_sServerName + ";" + "database=" + this.m_sDataBase + ";" +   "user id=" + this.m_sUserId + ";" + "password=" + this.m_sPassword;

  #region "打开连接（OpenConnection）"
   
        /// <returns>打开成功返回true，失败返回false</returns>
        public bool OpenConnection()
        {
            try
            {
                //-------检测连接是否已打开---------
                if (this.m_conObj.State == System.Data.ConnectionState.Open)
                    return true;
                //----------------------------------

                //-------打开连接--------
                this.m_conObj.ConnectionString = this.m_sConnectionString;
                this.m_conObj.Open();
                //-----------------------

                //-------检测连接状态--------
                if (this.m_conObj.State != System.Data.ConnectionState.Open)
                    this.m_sMessage = "打开连接失败！";
                //---------------------------
            }
            catch (Exception ex)
            {
                this.m_sMessage = ex.ToString();
                return false;
            }

            return true;
        }
        #endregion

       #region "关闭连接（CloseConnection）"
        public bool CloseConnection()
        {
            if (this.m_conObj.State == System.Data.ConnectionState.Open)
            {
                this.m_conObj.Close();
            }
            this.m_conObj.Dispose();

            return true;
        }
        #endregion

  #region "执行无返回值的sql语句（ExecuteNonQuery）"
        public bool ExecuteNonQuery(string p_sCommand)
        {
            //--------打开连接失败的话不执行查询---------
            if (!this.OpenConnection())
                return false;
            //-------------------------------------------

            try
            {
                SqlCommand cmdObj = this.m_conObj.CreateCommand();
                cmdObj.CommandText = p_sCommand;

               //----------------无返回值---------------------------
                cmdObj.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                this.m_sMessage = ex.ToString();
                return false;
            }
            finally
            {
                this.CloseConnection();
            }

            return true;
        }
        #endregion

        #region "执行单返回值的sql语句（ExecuteResult）"
        public object ExecuteResult(string p_sCommand)
        {
            object oReturn = null;

            //--------打开连接失败的话不执行查询---------
            if (!this.OpenConnection())
                return oReturn;
            //-------------------------------------------

            try
            {
                SqlCommand cmdObj = this.m_conObj.CreateCommand();
                cmdObj.CommandText = p_sCommand;
                oReturn = cmdObj.ExecuteScalar();//执行单返回值的sql语句
            }
            catch (Exception ex)
            {
                this.m_sMessage = ex.ToString();
            }
            finally
            {
                this.CloseConnection();
            }

            return oReturn;
        }
        #endregion

       #region "事务控制执行sql命令组（ExecuteSqlsByAffair）"
        public bool ExecuteSqlsByAffair(ArrayList p_oSqls)
        {
            //--------打开连接失败的话不执行查询---------
            if (!this.OpenConnection())
                return false;
            //-------------------------------------------

            SqlTransaction oTransaction = this.m_conObj.BeginTransaction();    //起动事务操作

            try
            {
                SqlCommand cmdObj = this.m_conObj.CreateCommand();
                cmdObj.Transaction = oTransaction;    //指定command对象的事务对象

                for (int i = 0; i < p_oSqls.Count; i++)
                {
                    cmdObj.CommandText = p_oSqls[i].ToString();
                    cmdObj.ExecuteNonQuery();
                }

                oTransaction.Commit();    //成功执行提交事务
            }
            catch (Exception ex)
            {
                oTransaction.Rollback();    //执行失败事务回滚
                this.m_sMessage = ex.ToString();

                return false;
            }
            finally
            {
                this.CloseConnection();
            }

            return true;
        }
        #endregion

 #region "获取数据表（GetDataTable）"

     public DataTable GetDataTable(string p_sCommand, string p_sTableName, int p_iCurrentPage, int p_iPageSize)
        {
            //--------打开连接失败的话不执行查询---------
            if (!this.OpenConnection())
                return null;
            //-------------------------------------------

            try
            {
                DataSet oDs = new DataSet();
                SqlCommand cmdObj = this.m_conObj.CreateCommand();
                cmdObj.CommandText = p_sCommand;
                SqlDataAdapter daObj = new SqlDataAdapter(cmdObj);
                daObj.Fill(oDs, (p_iCurrentPage - 1) * p_iPageSize, p_iPageSize, p_sTableName);
                return oDs.Tables[0];
            }
            catch (Exception ex)
            {
                this.m_sMessage = ex.ToString();
                return null;
            }
            finally
            {
                this.CloseConnection();
            }
        }
        #endregion