ASP.NET DBHelper类

using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Data.Common;
using System.Data;
namespace DownData.dal
{
    public static class DBHelper
    {
        private static readonly string connectionString =
            "Data Source=.\\newdb;Initial Catalog=downloaddata; uid=sa;pwd=sa";
        private static readonly string providerName ="System.Data.SqlClient";
        //GetConnection 用于获取连接数据库的 connection 对象...
        private static DbConnection GetConnection()
        {
            DbProviderFactory _factory = DbProviderFactories.GetFactory(providerName);
            DbConnection connection = _factory.CreateConnection();
            connection.ConnectionString = connectionString;
            return connection;
        }
        //GetCommand 获取命令参数 command 对象...
        private static DbCommand GetCommand(string commandText, CommandType commandType, DbConnection connection)
        {
            DbCommand command = connection.CreateCommand();
            command.CommandText = commandText;
            command.CommandType = commandType;