代码：
using System;
using System.Data;
using System.Configuration;
using System.Data.OleDb;
using ahwildlife.Utils; /// <summary>
/// AccessHelper 的摘要说明
/// </summary>
public class AccessHelper
{
#region 变量
protected static OleDbConnection conn = new OleDbConnection();
protected static OleDbCommand comm = new OleDbCommand();
protected static string connectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=ahwildlife.mdb;Persist Security Info=False;Jet OLEDB:Database Password=sa;";
#endregion #region 构造函数
/// <summary>
/// 构造函数
/// </summary>
public AccessHelper()
{ }
#endregion #region 打开数据库
/// <summary>
/// 打开数据库
/// </summary>
private static void openConnection()
{
if (conn.State == ConnectionState.Closed)
{
conn.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=ahwildlife.mdb;Persist Security Info=False;Jet OLEDB:Database Password=sa;";
comm.Connection = conn;
try
{
conn.Open();
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
}
}
#endregion #region 关闭数据库
/// <summary>
/// 关闭数据库
/// </summary>
private static void closeConnection()
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
conn.Dispose();
comm.Dispose();
}
}
#endregion #region 执行sql语句
/// <summary>
/// 执行sql语句
/// </summary>
public static void ExecuteSql(string sqlstr)
{
try
{
openConnection();
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
comm.ExecuteNonQuery();
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
finally
{
closeConnection();
}
}
#endregion #region 返回指定sql语句的OleDbDataReader对象,使用时请注意关闭这个对象。
/// <summary>
/// 返回指定sql语句的OleDbDataReader对象,使用时请注意关闭这个对象。
/// </summary>
public static OleDbDataReader DataReader(string sqlstr)
{
OleDbDataReader dr = null;
try
{
openConnection();
comm.CommandText = sqlstr;
comm.CommandType = CommandType.Text; dr = comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch
{
try
{
dr.Close();
closeConnection();
}
catch { }
}
return dr;
}
#endregion #region 返回指定sql语句的OleDbDataReader对象,使用时请注意关闭
/// <summary>
/// 返回指定sql语句的OleDbDataReader对象,使用时请注意关闭
/// </summary>
public static void DataReader(string sqlstr, ref OleDbDataReader dr)
{
try
{
openConnection();
comm.CommandText = sqlstr;
comm.CommandType = CommandType.Text;
dr = comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch
{
try
{
if (dr != null && !dr.IsClosed)
dr.Close();
}
catch
{
}
finally
{
closeConnection();
}
}
}
#endregion #region 返回指定sql语句的DataSet
/// <summary>
/// 返回指定sql语句的DataSet
/// </summary>
/// <param name="sqlstr"></param>
/// <returns></returns>
public static DataSet DataSet(string sqlstr)
{
DataSet ds = new DataSet();
OleDbDataAdapter da = new OleDbDataAdapter();
try
{
openConnection();
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
da.SelectCommand = comm;
da.Fill(ds); }
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
return ds;
}
#endregion #region 返回指定sql语句的DataSet
/// <summary>
/// 返回指定sql语句的DataSet
/// </summary>
/// <param name="sqlstr"></param>
/// <param name="ds"></param>
public static void DataSet(string sqlstr, ref DataSet ds)
{
OleDbDataAdapter da = new OleDbDataAdapter();
try
{
openConnection();
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
da.SelectCommand = comm;
da.Fill(ds);
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
}
#endregion #region 返回指定sql语句的DataTable
/// <summary>
/// 返回指定sql语句的DataTable
/// </summary>
/// <param name="sqlstr"></param>
/// <returns></returns>
public static DataTable DataTable(string sqlstr)
{
DataTable dt = Common.GetDataTableCache(sqlstr);//读缓存
if (dt != null)
{
return dt.Copy();
}
else
{
dt = new DataTable();
OleDbDataAdapter da = new OleDbDataAdapter();
try
{
using (OleDbConnection conn = new OleDbConnection())
{
conn.ConnectionString = connectionString;
conn.Open();
using (OleDbCommand comm = new OleDbCommand())
{
comm.Connection = conn;
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
da.SelectCommand = comm;
da.Fill(dt);
}
}
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
Common.InsertDataTableCache(sqlstr, dt);//添加缓存
return dt.Copy();
}
}
#endregion #region 返回指定sql语句的DataTable
/// <summary>
/// 返回指定sql语句的DataTable
/// </summary>
public static void DataTable(string sqlstr, ref DataTable dt)
{
OleDbDataAdapter da = new OleDbDataAdapter();
try
{
openConnection();
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
da.SelectCommand = comm;
da.Fill(dt);
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
}
#endregion #region 返回指定sql语句的DataView
/// <summary>
/// 返回指定sql语句的DataView
/// </summary>
/// <param name="sqlstr"></param>
/// <returns></returns>
public static DataView DataView(string sqlstr)
{
OleDbDataAdapter da = new OleDbDataAdapter();
DataView dv = new DataView();
DataSet ds = new DataSet();
try
{
openConnection();
comm.CommandType = CommandType.Text;
comm.CommandText = sqlstr;
da.SelectCommand = comm;
da.Fill(ds);
dv = ds.Tables[].DefaultView;
}
catch (Exception e)
{
throw new Exception(e.Message);
}
finally
{
closeConnection();
}
return dv;
}
#endregion }