1、OleDbDataReader用于从数据库中读取数据，参考代码如下：

OleDbConnection conn = new OleDbConnection();conn.ConnectionString = @"Provider=microsoft.ace.oledb.12.0;Data Source=|DataDirectory|湖州工厂故障现象及原因数据库.accdb;";//查找故障现象表中有几行，用于下面定义数组大小用OleDbCommand com = new OleDbCommand("SELECT COUNT(故障现象代码) AS NUM FROM 故障现象", conn);conn.Open();OleDbDataReader drNew = com.ExecuteReader();drNew.Read();int F_rows = int.Parse(drNew["NUM"].ToString());drNew.Close();conn.Close();

2、OleDbDataAdapter用于链接数据库，供DataSet使用，代码如下：

OleDbConnection conn = new OleDbConnection();conn.ConnectionString = @"Provider=microsoft.ace.oledb.12.0;Data Source=|DataDirectory|湖州工厂故障现象及原因数据库.accdb;";//获得故障现象表中的故障现象列表OleDbDataAdapter Fname_Adapter = new OleDbDataAdapter("select 故障现象 from 故障现象", conn);DataSet Fname_table = new DataSet();Fname_Adapter.Fill(Fname_table, "故障现象");int Fname_sum = Fname_table.Tables["故障现象"].Rows.Count;string[] Fname = new string[Fname_sum];for (int i = 0; i < Fname_table.Tables["故障现象"].Rows.Count;i++ ){ Fname[i] = (string)Fname_table.Tables["故障现象"].Rows[i]["故障现象"];}Fname_table.Dispose();int[] F_times = new int[Fname_sum];//获取查询记录中Fxxx的原始数据（这个数据有些是重复的，要对其进行处理）。OleDbDataAdapter Fxxx_Adapter = new OleDbDataAdapter("select 故障现象 from 故障记录", conn);DataSet Fxxx_table = new DataSet();Fxxx_Adapter.Fill(Fxxx_table, "故障记录");//string iii = (string)Fxxx_table.Tables["故障记录"].Rows[2]["故障现象"];int F_contents_sum = Fxxx_table.Tables["故障记录"].Rows.Count; //有几条故障记录string[] F_contents = new string[F_contents_sum];for (int j = 0; j < F_contents_sum; j++){ F_contents[j] = (string)Fxxx_table.Tables["故障记录"].Rows[j]["故障现象"];}for (int j = 0; j < F_contents_sum; j++){ for(int k=0;k<Fname_sum;k++) { if (F_contents[j] == Fname[k]) F_times[k]++; }}Fxxx_table.Dispose();