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这几篇是是在MFC框架下做保险项目的学习心得,只学了两周,但是还是学了很多知识。 下面介绍一下用ADO来进行数据库的各种操作。 1、数据库连接和打开 这次项目用的是SQL Server数据库,ADO连接数据遇到最重要的问题就是找到连接字符串,经过亲身经历各种尝试,在网上发现了一种无bug的方法,就是通过新建ado.udl文件,然后打开填写相应的数据库后用记事本打开即可得到连接字符串。下面是我封装的一个打开数据库的方法:
1 BOOL CDateOperator::OpenDateBase() 2 { 3 4 if(NULL == m_pConnection){ 5 AfxMessageBox(L"Create Instance failed!"); 6 return FALSE; 7 } 8 if(m_pConnection){ 9 10 11 try 12 { 13 14 const _bstr_t strSRC= "Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=mydb;Data Source=LI5CH\\SQLEXPRESS"; 15 16 HRESULT hr = m_pConnection->Open(strSRC,L"",L"",-1); 17 } 18 catch(_com_error &e) 19 { 20 CString errormsg; 21 errormsg.Format(L"关闭连接——操作错误!\r\n错误信息:%s",e.ErrorMessage()); 22 AfxMessageBox(errormsg); 23 24 } 25 26 } 27 return TRUE; 28 29 }
2、ADO如何执行sql语句
BOOL CDateOperator::ExcuteSQL(CString strSQL){ if(NULL == m_pConnection) return FALSE; try { HRESULT hr = m_pConnection->Execute(_bstr_t(strSQL),NULL,-1); } catch(_com_error &e) { return FALSE; } return TRUE; }
3、ADO如何插入记录
BOOL CDateOperator::Insert_db(DEMO objuser) { if(NULL == m_pConnection) return FALSE; _RecordsetPtr m_pRecordset; HRESULT hr = m_pRecordset.CreateInstance(L"ADODB.Recordset"); if(FAILED(hr)) return FALSE; CString strSQL = L"SELECT User_ID, User_Name FROM fate"; hr = m_pRecordset->Open(_bstr_t(strSQL),m_pConnection.GetInterfacePtr(),adOpenStatic,adLockOptimistic,adCmdText); if(FAILED(hr)){ m_pRecordset.Release(); return FALSE; } try { m_pRecordset->AddNew(); } catch(_com_error &e) { m_pRecordset->Close(); m_pRecordset.Release(); return FALSE; } // byte byData[10000]; try { m_pRecordset->PutCollect("User_ID",_variant_t(objuser.User_ID)); m_pRecordset->PutCollect("User_Name",_variant_t(objuser.User_Name)); } catch(_com_error &e) { m_pRecordset->Close(); m_pRecordset.Release(); return FALSE; } m_pRecordset->Update(); m_pRecordset->Close(); m_pRecordset.Release(); return TRUE; }
4、ADO如何查询数据
BOOL CDateOperator::Select_db(vector<DEMO>& vecObjUser) { if(NULL == m_pConnection) return FALSE; _RecordsetPtr m_pRecordset; HRESULT hr = m_pRecordset.CreateInstance(L"ADODB.Recordset"); if(FAILED(hr)) return FALSE; vecObjUser.clear(); CString strSQL = L"SELECT User_ID, User_Name FROM fate"; hr = m_pRecordset->Open(_bstr_t(strSQL),m_pConnection.GetInterfacePtr(),adOpenStatic,adLockOptimistic,adCmdText); if(FAILED(hr)){ m_pRecordset.Release(); return FALSE; } VARIANT_BOOL bRet = m_pRecordset->GetadoEOF(); while(!bRet){ _variant_t varUserID = m_pRecordset->GetCollect(L"User_ID"); _variant_t varUserName = m_pRecordset->GetCollect(L"User_Name"); DEMO objUser; objUser.User_ID=varUserID.intVal; _tcscpy(objUser.User_Name,(TCHAR*)(_bstr_t)varUserName); vecObjUser.push_back(objUser); m_pRecordset->MoveNext(); bRet = m_pRecordset->GetadoEOF(); } m_pRecordset->Close(); m_pRecordset.Release(); return TRUE; }
5、ADO如何更新数据
BOOL CDateOperator::update_db(DEMO objuser) { if(NULL == m_pConnection) return FALSE; _RecordsetPtr m_pRecordset; HRESULT hr = m_pRecordset.CreateInstance(L"ADODB.Recordset"); if(FAILED(hr)) return FALSE; CString strSQL; strSQL.Format(L"SELECT User_ID, User_Name FROM fate WHERE User_ID=%d", objuser.User_ID); hr = m_pRecordset->Open(_bstr_t(strSQL),m_pConnection.GetInterfacePtr(),adOpenStatic,adLockOptimistic,adCmdText); if(FAILED(hr)){ m_pRecordset.Release(); return FALSE; } // byte byData[10000]; try { m_pRecordset->PutCollect("User_Name",_variant_t(objuser.User_Name)); } catch(_com_error &e) { m_pRecordset->Close(); m_pRecordset.Release(); return FALSE; } m_pRecordset->Update(); m_pRecordset->Close(); m_pRecordset.Release(); return TRUE; }
6、下面贴一下构造和析构函数
CDateOperator::CDateOperator(void) { try { HRESULT hr = m_pConnection.CreateInstance("ADODB.Connection"); if(FAILED(hr)) { AfxMessageBox(L"Create Instance failed!"); m_pConnection = NULL; } } catch(_com_error &e) { } } CDateOperator::~CDateOperator(void) { if(m_pConnection) { try { HRESULT hr = m_pConnection->Close(); } catch(_com_error &e) { } } m_pConnection.Release(); m_pConnection = NULL; }
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原文地址:http://www.cnblogs.com/li5ch/p/4527615.html