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[0].DefaultView;}catch (Exception e){throw new Exception(e.Message);}finally{closeConnection();}return dv;}#endregion}