VC++连接SQL数据库，并获取相应查询内容
前几天用VC++，获取SQL中的内容并保存，由于不是很熟悉，走了很多弯路，现在总结哈，希望能给需要的人一些帮助。
直接贴代码。
#include "string"#include "map"//连接SQL引用的#import "C:\Program Files\Common Files\System\ado\msado15.dll"no_namespace rename("EOF","ADOEOF")using namespace std;//你自己定义的函数void XXXDlg::YourFun() {// TODO: Add your control notification handler code here::CoInitialize(NULL);_ConnectionPtr m_pConnection("ADODB.Recordset");_RecordsetPtr m_pRecordset("ADODB.Recordset");_CommandPtr m_pCommand;//连接数据库信息，写在ini文件中的，filepath是ini文件的路径//ini文件内容：//[Info]//Database = driver={SQL Server};Server=数据库电脑ip地址（比如本机127.0.0.1）,1433;Database=数据库名称;//name = 数据库名字//pwd = 你的数据库密码//filepath1 = F:///filepath2 = .txtCString Database;GetPrivateProfileString("Info", "Database", "", Database.GetBuffer(MAX_PATH), MAX_PATH, filepath);//将获取的数据库链接字段，转换成指定格式_bstr_t strConnect = Database;//数据库连接try{m_pConnection.CreateInstance(__uuidof(Connection));CString name;CString pwd;GetPrivateProfileString("Info", "name", "", name.GetBuffer(MAX_PATH), MAX_PATH, filepath);GetPrivateProfileString("Info", "pwd", "", pwd.GetBuffer(MAX_PATH), MAX_PATH, filepath);_bstr_t name1 = name;_bstr_t pwd1 = pwd;HRESULT ConnectResult = m_pConnection->Open(strConnect,name1,pwd1,adModeUnknown);if(SUCCEEDED(ConnectResult)){MessageBox("连接数据库成功！");}}catch(_com_error e){MessageBox("连接数据库失败！");return;}//查询相关内容信息try{_bstr_t CommandText = "select a.字段1,b.字段2,b.字段3,b.字段4 from 表名1 a,表名2 b where 相关条件";//m_pConnection->Execute(CommandText, NULL, adCmdText);m_pRecordset.CreateInstance(__uuidof(Recordset));m_pRecordset->Open(CommandText, m_pConnection.GetInterfacePtr(), adOpenDynamic, adLockOptimistic, adCmdText);_variant_t 字段1Result;_variant_t 字段2Result;_variant_t 字段3Result;_variant_t 字段4Result;//我是将读出来的信息，保存到txt文件中//下面是从ini文件中读取保存文件的地址CString filepath1;CString filepath2;GetPrivateProfileString("Info", "filepath1", "", filepath1.GetBuffer(MAX_PATH), MAX_PATH, filepath);GetPrivateProfileString("Info", "filepath2", "", filepath2.GetBuffer(MAX_PATH), MAX_PATH, filepath);string m1 = filepath1.GetBuffer(0);string m2 = filepath2.GetBuffer(0);CString m3 = m1.c_str();CString m4 = m2.c_str();//定义一个map容器以免，重复操作文件的打开关闭操作map<string, auto_ptr<CStdioFile> > filename;//遍历查询结果，并保存while(!m_pRecordset->ADOEOF){字段1Result = m_pRecordset->GetCollect("字段1");CString 字段1Results;字段Results=(LPCSTR)_bstr_t(字段1Result);CString fileEnd = m3 + 字段1Results + m4;//我是以 字段1 为文件名保存其他三个字段的内容CStdioFile* pfile = NULL;if(filename.find((LPCSTR)fileEnd)!=filename.end()){pfile = filename[(LPCSTR)fileEnd].get();}else{pfile = new CStdioFile(fileEnd,CFile::modeCreate|CFile::modeNoTruncate|CFile::modeWrite);filename[(LPCSTR)fileEnd] = auto_ptr<CStdioFile>(pfile);}字段2Result = m_pRecordset->GetCollect("字段2");CString 字段2Results;字段2Results=(LPCSTR)_bstr_t(字段2Result);pfile->SeekToEnd();//先定位到文件尾部pfile->WriteString(字段2Results);//写入文件pfile->WriteString("\t");//每个字段内容用talbe键分开字段3Result = m_pRecordset->GetCollect("字段3");CString 字段3Results;字段3Results=(LPCSTR)_bstr_t(字段3Result);pfile->SeekToEnd();//先定位到文件尾部pfile->WriteString(字段3Results);pfile->WriteString("\t");字段4Result = m_pRecordset->GetCollect("字段4");CString 字段4Results;字段4Results=(LPCSTR)_bstr_t(字段4Result);pfile->SeekToEnd();//先定位到文件尾部pfile->WriteString(字段4Results);pfile->WriteString("\r\n");//每条记录一行，记录完换行m_pRecordset->MoveNext();//记录完一条记录，指向下一条记录}//循环关闭打开的文件指针map<string,auto_ptr<CStdioFile> >::const_iterator map_it = filename.begin();while(map_it!=filename.end()){(map_it->second)->Close();map_it++;}filename.clear();//MessageBox(s);}catch(_com_error e){return;}}
才疏学浅，如有不对，望海涵，哈哈。