using  System;
 using  System.Data;
 using  System.Data.OleDb;
 using  System.Web;
 using  System.Web.UI;
 using  System.Configuration;

 namespace  Com.LXJ.Database
{
 ///   <summary> 
 ///  conn 的摘要说明。
 ///   </summary> 
   public   class  ConnDbForAcccess
 {
 ///   <summary> 
 ///  连接数据库字符串
 ///   </summary> 
   private   string  connectionString;

 ///   <summary> 
 ///  存储数据库连接（保护类，只有由它派生的类才能访问）
 ///   </summary> 
   protected  OleDbConnection Connection;

 ///   <summary> 
 ///  构造函数：数据库的默认连接
 ///   </summary> 
   public  ConnDbForAcccess()
 {
 string  connStr;
 connStr  =  ConfigurationManager.ConnectionStrings[ " ConnectionString " ].ConnectionString.ToString();
 //  connStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString();  // 从web.config配置中读取 
  connectionString  =  connStr;
 // connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + HttpContext.Current.Request.PhysicalApplicationPath + connStr;
 //  connectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"].ToString();
 //
  Connection  =   new  OleDbConnection(connectionString);
 }

 ///   <summary> 
 ///  构造函数：带有参数的数据库连接
 ///   </summary> 
 ///   <param name="newConnectionString"></param> 
   public  ConnDbForAcccess( string  newConnectionString)
 {
 // connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + HttpContext.Current.Request.PhysicalApplicationPath + newConnectionString; 
  connectionString  =  newConnectionString;
 Connection  =   new  OleDbConnection(connectionString);
 }

 ///   <summary> 
 ///  获得连接字符串
 ///   </summary> 
   public   string  ConnectionString
 {
 get 
 {
 return  connectionString;
 }
 }


 ///   <summary> 
 ///  执行SQL语句没有返回结果，如：执行删除、更新、插入等操作
 ///   </summary> 
 ///   <param name="strSQL"></param> 
 ///   <returns> 操作成功标志 </returns> 
   public   bool  ExeSQL( string  strSQL)
 {
 bool  resultState  =   false ;

 Connection.Open();
 OleDbTransaction myTrans  =  Connection.BeginTransaction();
 OleDbCommand command  =   new  OleDbCommand(strSQL, Connection, myTrans);

 try 
 {
 command.ExecuteNonQuery();
 myTrans.Commit();
 resultState  =   true ;
 }
 catch 
 {
 myTrans.Rollback();
 resultState  =   false ;
 }
 finally 
 {
 Connection.Close();
 }
 return  resultState;
 }

 ///   <summary> 
 ///  执行SQL语句返回结果到DataReader中
 ///   </summary> 
 ///   <param name="strSQL"></param> 
 ///   <returns> dataReader </returns> 
   private  OleDbDataReader ReturnDataReader( string  strSQL)
 {
 Connection.Open();
 OleDbCommand command  =   new  OleDbCommand(strSQL, Connection);
 OleDbDataReader dataReader  =  command.ExecuteReader();
 Connection.Close();

 return  dataReader;
 }

 ///   <summary> 
 ///  执行SQL语句返回结果到DataSet中
 ///   </summary> 
 ///   <param name="strSQL"></param> 
 ///   <returns> DataSet </returns> 
   public  DataSet ReturnDataSet( string  strSQL)
 {
 Connection.Open();
 DataSet dataSet  =   new  DataSet();
 OleDbDataAdapter OleDbDA  =   new  OleDbDataAdapter(strSQL, Connection);
 OleDbDA.Fill(dataSet,  " objDataSet " );

 Connection.Close();
 return  dataSet;
 }

 ///   <summary> 
 ///  执行一查询语句，同时返回查询结果数目
 ///   </summary> 
 ///   <param name="strSQL"></param> 
 ///   <returns> sqlResultCount </returns> 
   public   int  ReturnSqlResultCount( string  strSQL)
 {
 int  sqlResultCount  =   0 ;

 try 
 {
 Connection.Open();
 OleDbCommand command  =   new  OleDbCommand(strSQL, Connection);
 OleDbDataReader dataReader  =  command.ExecuteReader();

 while  (dataReader.Read())
 {
 sqlResultCount ++ ;
 }
 dataReader.Close();
 }
 catch 
 {
 sqlResultCount  =   0 ;
 }
 finally 
 {
 Connection.Close();
 }
 return  sqlResultCount;
 }


 } //
 } //