C# DBHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;

namespace HotelManage
{


    class DBHelper
    {
        //数据库连接字符串
        private static string connectionString = "Data Source =.; Initial Catalog = Hotel; Integrated Security = SSPI";

        /// <summary>
        /// 执行SQL语句，返回影响的记录数
        /// </summary>
        /// <param name="SQLString">SQL语句</param>
        /// <returns>影响的记录数</returns>
        public static int ExecuteSql(string SQLString)
        {
            SqlConnection connection = new SqlConnection(connectionString);
            SqlCommand cmd = new SqlCommand(SQLString, connection);
            try
               {
                   connection.Open();
                   int rows = cmd.ExecuteNonQuery();
                   return rows;
               }
               catch (System.Data.SqlClient.SqlException e)
               {
                   connection.Close();
                   throw e;
               }
        }


        /// <summary>
        /// 执行查询语句，返回DataSet
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataSet GetDataSet(string SQLString)
        {
            SqlConnection connection = new SqlConnection(connectionString);
            DataSet ds = new DataSet();
            try
            {
                connection.Open();
                SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                command.Fill(ds, "ds");
            }
            catch (System.Data.SqlClient.SqlException ex)
            {
                throw new Exception(ex.Message);
            }
            return ds;
        }

    }


}