using System;        using System.Collections.Generic;        using System.Linq;        using System.Text;        using System.Data;        using System.Data.OleDb;                        namespace AccessPractice        {            public static class AccessHelper            {                public static bool Execute(string path,string sql)                 {                    try                    {                        string strConn = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";";                        OleDbConnection odcConnection = new OleDbConnection(strConn);                        //2、打开连接                        odcConnection.Open();                        //建立SQL查询                        OleDbCommand odCommand = odcConnection.CreateCommand();                        //3、输入查询语句                        odCommand.CommandText = sql;                                        odCommand.ExecuteNonQuery();                        odcConnection.Close();                        return true;                    }                    catch(Exception ex)                    {                        return false;                    }                                }                                public static DataTable ReadAllData(string tableName, string mdbPath,int topN, ref bool success)                {                    DataTable dt = new DataTable();                    try                    {                        //1、建立连接                        string strConn = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + mdbPath + ";";                        OleDbConnection odcConnection = new OleDbConnection(strConn);                        //2、打开连接                        odcConnection.Open();                        //建立SQL查询                        OleDbCommand odCommand = odcConnection.CreateCommand();                        //3、输入查询语句                        odCommand.CommandText = "select * from " + tableName;                        //建立读取                        OleDbDataReader odrReader = odCommand.ExecuteReader();                        //查询并显示数据                        int size = odrReader.FieldCount;                        for (int i = 0; i < size; i++)                        {                            DataColumn dc;                            dc = new DataColumn(odrReader.GetName(i));                            dt.Columns.Add(dc);                        }                        DataRow dr;                        int count = 0;                        while (odrReader.Read())                        {                            if (++count == topN)                             {                                break;                            }                            dr = dt.NewRow();                            for (int i = 0; i < size; i++)                            {                                dr[odrReader.GetName(i)] = odrReader[odrReader.GetName(i)].ToString();                            }                            dt.Rows.Add(dr);                        }                        //关闭连接                        odrReader.Close();                        odcConnection.Close();                        success = true;                        return dt;                    }                    catch                    {                        success = false;                        return dt;                    }                }                            }        }