简单ADO编程源代码分析

本示例程序是利用ODBC DSN方法来连接数据库的，测试环境为：Visual Stdio 2010，开发语言为C++。其程序源代码如下：

// ADO.cpp : Defines the entry point for the console application.//#include "stdafx.h"#include <iostream>#include <string>#include <vector>#include <afx.h>#import "C:/Program Files/Common Files/System/ado/msado15.dll" no_namespace rename("EOF", "adoEOF")using namespace std;int _tmain(int argc, _TCHAR* argv[]){CoInitialize(NULL);//Initialize the com enviroment_ConnectionPtr pMyConnect(__uuidof(Connection));//定义连接对象并实例化对象_RecordsetPtr pRst(__uuidof(Recordset));//定义记录集对象并实例化对象try{//打开数据库//CString strConnect="DRIVER={Provider=Microsoft.Jet.OLEDB.4.0;Microsoft Access Driver(*.mdb)};uid=;pwd=;DBQ=F://C++ study//ADO//ADO//shujuku.mdb;";CString strConnect="DSN=RocketsPlayers;/DBQ=F://C++ study//源程序//源程序//chap13//RocketsPlayers.mdb;/DriverId=25;FIL=MS Access;MaxBufferSize=2048;PageTimeout=5;";//CString strConnect="Provider=SQLOLEDB;Data Source=F://C++ study//ADO//ADO//shujuku.mdb;";pMyConnect->Open((_bstr_t)strConnect,"","",NULL);//pMyConnect->Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=shujuku.mdb;Persist Security Inof=False;","","",adModeUnknown);}catch(_com_error &e){cout<<"Initialize database failed"<<endl;cout<<e.Description()<<endl;cout<<e.HelpFile()<<endl;return 0;}cout<<"Connect database success!"<<endl;try{pRst = pMyConnect->Execute("select * from Rockets", NULL, adCmdText);if(!pRst->BOF){pRst->MoveFirst();}else{cout<<"The data in the table is null"<<endl;return 0;}//存储表的所有列名vector<_bstr_t> column_name;for(int i=0; i<pRst->Fields->GetCount();i++){cout<<pRst->Fields->GetItem(_variant_t((long)i))->Name<<"/t";column_name.push_back(pRst->Fields->GetItem(_variant_t((long)i))->Name);}cout<<endl;//对表进行遍历访问while(!pRst->adoEOF){vector<_bstr_t>::iterator iter = column_name.begin();/*for(iter;iter!=column_name.end();iter++){*/if(pRst->GetCollect(*iter).vt != VT_NULL){//cout<<(_bstr_t)pRst->GetCollect(*iter)<<"/t/t i="<<i<<endl;cout<<"/t"<<(_bstr_t)pRst->Fields->Item[_variant_t("PlayerID")]->Value;cout<<"/t"<<(_bstr_t)pRst->Fields->Item[_variant_t("Name")]->Value;cout<<"/t"<<(_bstr_t)pRst->Fields->Item[_variant_t("Number")]->Value;cout<<"/t"<<(_bstr_t)pRst->Fields->Item[_variant_t("Age")]->Value;cout<<"/t"<<(_bstr_t)pRst->Fields->Item[_variant_t("State")]->Value;cout<<"/t"<<(_bstr_t)pRst->Fields->Item[_variant_t("Height")]->Value;cout<<"/t"<<(_bstr_t)pRst->Fields->Item[_variant_t("Weight")]->Value;}else{cout<<"NULL"<<endl;}pRst->MoveNext();//关闭记录集cout<<endl;//}}}catch(_com_error &e){cout<<e.Description()<<endl;cout<<e.HelpFile()<<endl;return 0;}//关闭数据库并释放指针try{pRst->Close();//关闭记录集pMyConnect->Close();//关闭数据库pRst.Release();//释放记录集对象指针pMyConnect.Release();//释放连接对象指针}catch(_com_error &e){cout<<e.Description()<<endl;cout<<e.HelpFile()<<endl;return 0;}CoUninitialize();//释放COM环境return 0;}

其执行结果如下：