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[]vc中应用ADOaccess

发布时间: 2012-12-19 14:13:14 作者: rapoo

[]vc中使用ADOaccess

//dbDemoConsole.cpp : Defines the entry point for the console //application./*#include "stdafx.h"int main(int argc, char* argv[]){printf("Hello World!\n");return 0;}*//*明:境:VC6.0工程:MFC console程序,模板是hello world(它自生成一main()代:整段代替代整cpp即可源:上文摘及cdsn vc.chm*//*注意:於_RecordsetPtr1)什候用close()?   於_RecordsetPtr,如果最後一次不是行open(select from),不需要close!否有常。   而且如果最後一次是open,必要住close,否再次open有常   貌似在Putcollect()後面也要close(),否再open()也常。2)什候用Update()?   Execute()不能用update,在putcollect()後面才要update()   不,putcollect()後面要不要update(),都可以存在中,不管後面是否update()直接就close()掉*/#include "stdafx.h"#include <iostream.h>//用#import指令引入ADO型#import "c:\program files\common files\system\ado\msado15.dll" no_namespace rename ("EOF", "adoEOF")int main(int argc, char* argv[]){//使用ADO接...//---------------------------------------------_ConnectionPtr m_pConnection; HRESULT hr;//在MFC中可以用AfxOleInit();非MFC境中用CoInitialize CoInitialize(NULL); try{   //m_pConnection.CreateInstance(__uuidof(Connection));   //也行   hr=m_pConnection.CreateInstance("ADODB.Connection");///建Connection象   // 在ADO操作中建句中要常用try...catch()捕信息,   // 因它有常出一些想不到的。   if(SUCCEEDED(hr))   {    // 打本地Access,路中必用\\,如果在源目(不是指debug下,而是代文件目)下只要Source=testdb.mdb即可     m_pConnection->Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\myProgramLib\\vc程序\\accessdb\\testdb.mdb","","",adModeUnknown);   }}catch(_com_error e){   cout<<e.ErrorMessage()<<"\r\n"<<"接失,db1.mdb是否在前路下!"<<endl;   return FALSE;   /*   CString errormessage;   errormessage.Format("接失!\r\n信息:%s",e.ErrorMessage());   AfxMessageBox(errormessage);///示信息   */} //-------------------------------------------------//建立集//-------------------------------------------------_RecordsetPtr m_pRecordset;m_pRecordset.CreateInstance(__uuidof(Recordset));//-------------------------------------------------//CSDN.chm句//-------------------------------------------------_variant_t RecordsAffected;try{// m_pRecordset =m_pConnection->Execute("Select Count(*) AS Qty FROM MSysObjects Where MSysObjects.Name=\"users\")",&RecordsAffected,adCmdText);// _variant_t lHave = m_pRecordset->GetCollect((long)0);   //TODO: 如何判access是否已存在某表了?   _variant_t lHave;   lHave.lVal=1;   if (lHave.lVal<=0)   {    cout<<"table users not exists,then create it!"<<endl;    ///行SQL命令:CREATE TABLE建表格users,users包含四字段:整形ID,字符串username,整形old,日期型birthday    m_pConnection->Execute("CREATE TABLE users(ID INTEGER,username TEXT,old INTEGER,birthday DATETIME)",&RecordsAffected,adCmdText);    ///往表格面添加      //!!於含有引的直接用\(\"三\")就可以了,不要像上面的一堆''''''''三'''''''',通不,也不知道啥??    m_pConnection->Execute("INSERT INTO users(ID,username,old,birthday) valueS (1, \"三\",22,\"1970/1/1\")",&RecordsAffected,adCmdText);    ///所有old字段的值加一    m_pConnection->Execute("UPDATE users SET old = old+1",&RecordsAffected,adCmdText);    //m_pRecordset->Update();   //不能用update,因不是putcollect()    ///行SQL命令得到包含的集    m_pRecordset = m_pConnection->Execute("SELECT COUNT(*) FROM users",&RecordsAffected,adCmdText);    _variant_t vIndex = (long)0;    _variant_t vCount = m_pRecordset->GetCollect(vIndex);///取得第一字段的值放入vCount量      //message.Format("共有%d",);    cout<<"共有"<<vCount.lVal<<""<<endl;       m_pRecordset->Close();///集 --因有select,必close,後面才能再open   }   else   {    cout<<"table users   exists,then not create it!"<<endl;   }}catch(_com_error *e){   cout<<e->ErrorMessage()<<endl;}//根我才通行SQL命令建立好的users表,它包含四字段:ID,username,old,birthday//以下的代:打集,遍所有,除第一,添加三,移光到第二,更改其年,保存到。_variant_t vUsername,vBirthday,vID,vOld;//m_pConnection.GetInterfacePtr() 或 _variant_t((IDispatch*)m_pConnection,true)m_pRecordset->Open("SELECT * FROM users",m_pConnection.GetInterfacePtr(),adOpenStatic,adLockOptimistic,adCmdText);if(!m_pRecordset->BOF)m_pRecordset->MoveFirst();else{cout<<"表空"<<endl;return 1;}while(!m_pRecordset->adoEOF)///什是adoEOF而不是EOF呢?得rename("EOF","adoEOF")一句?{   vID = m_pRecordset->GetCollect(_variant_t((long)0));///取得第1列的值,0始,你也可以直接出列的名,如下一行   vUsername = m_pRecordset->GetCollect("username");///取得username字段的值   vOld = m_pRecordset->GetCollect("old");   vBirthday = m_pRecordset->GetCollect("birthday");   ///在DEBUG方式下的OUTPUT窗口出集中的   if(vID.vt != VT_NULL && vUsername.vt != VT_NULL && vOld.vt != VT_NULL && vBirthday.vt != VT_NULL)    //TRACE("id:%d,姓名:%s,年:%d,生日:%s\r\n",vID.lVal,(LPCTSTR)(_bstr_t)vUsername,vOld.lVal,(LPCTSTR)(_bstr_t)vBirthday);    cout<<"id:"<<vID.lVal<<",姓名:"<<(LPCTSTR)(_bstr_t)vUsername<<",年:"<<vOld.lVal<<",生日:"<<(LPCTSTR)(_bstr_t)vBirthday<<"\r\n";    m_pRecordset->MoveNext();///移到下一}m_pRecordset->MoveFirst();///移到首m_pRecordset->Delete(adAffectCurrent);///除前///添加三新值for(int i=0;i<3;i++){   m_pRecordset->AddNew();///添加新   m_pRecordset->PutCollect("ID",_variant_t((long)(i+10)));   m_pRecordset->PutCollect("username",_variant_t(""));   m_pRecordset->PutCollect("old",_variant_t((long)71));   m_pRecordset->PutCollect("birthday",_variant_t("1930-3-15"));}m_pRecordset->Move(1,_variant_t((long)adBookmarkFirst));///第一往下移一,即移到第二m_pRecordset->PutCollect(_variant_t("old"),_variant_t((long)45));///修改其年// m_pRecordset->Update();///保存到中 --好像有update()都可以更新到的??//-------------------------------------------------//CSDN.chm句 <end>//-------------------------------------------------//--------------------------------------------------//取//--------------------------------------------------/*   _variant_t var;    char *strID,*strX,*strY;   float X,Y;   // 入中各字段加入列表框中   while(!m_pRecordset->adoEOF)   {    var = m_pRecordset->GetCollect("ID");    if(var.vt != VT_NULL)    strID= _com_util::ConvertBSTRToString((_bstr_t)var); //_variant_t字符串    var = m_pRecordset->GetCollect("WNX");    if(var.vt != VT_NULL)    strX=_com_util::ConvertBSTRToString((_bstr_t)var);    var = m_pRecordset->GetCollect("WNY");    if(var.vt != VT_NULL)    strY=_com_util::ConvertBSTRToString((_bstr_t)var);    cout<<strID<<"is"<<strX<<" "<<strY<<endl;    m_pRecordset->MoveNext();   } }catch(_com_error *e){   cout<<e->ErrorMessage()<<endl;} *///--------------------------------------------------//集// m_pRecordset->Close();m_pRecordset = NULL; //--------------------------------------------------//接//--------------------------------------------------if(m_pConnection->State)   m_pConnection->Close();m_pConnection= NULL;return 0;}



自:http://hi.baidu.com/liutao198792/blog/item/f7b0fcdf7633835fcdbf1a17.html

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