从vc连接到oracle数据库从vc连接到oracle数据库

/*************************************************************** @author Chandar @version 1.0 Development Environment : Visual C++ 6.0 Name of the File : OLEHandler.cpp Creation/Modification History : 07-Aug-2001 Created File Overview This file implements the DBHandler class and its functions which is used by the application to communicate to the database. '*****************************************************************/ #include "StdAfx.h" #include <atldbcli.h> #include "ConnectionParams.h" #define UNICODE #define DBINITCONSTANTS #define INITGUID #include "OraOLEDB.h" #include "OLEHandler.h" //Variable declaration const ULONG nInitProps=4; const ULONG nPropSet=3; const ULONG nParams=5; //Number of parameters in the command DBPROP InitProperties[nInitProps]; DBPROPSET rgInitPropSet[nPropSet]; DBPARAMBINDINFO ParamBindInfo[nParams]; ULONG ParamOrdinals[nParams]; HRESULT hr; //Constructor definition DBHandler::DBHandler() { cbColOffset = 0; pRows = &hRows[0]; cNumRows = 0; } /* Declare an array of DBBINDING structures, one for each parameter in the command. */ DBBINDING acDBBinding[nParams]; DBBINDSTATUS acDBBindStatus[nParams]; //The following buffer is used to store parameter values. typedef struct tagSPROCPARAMS { BSTR languageid; int productid; BSTR tname; BSTR tdescription; int check; }SPROCPARAMS; /********************************************************************** This function is used to intialize the database properties and get a connection to it in following steps: 1. Call CoCreateInstance specifying the provider to obtain access to it. 2. Set the properties and values of database in DBPROP struct 3 Create a array of properties using DBPROPSET struct 4. Pass this array to initialize the database connection ***********************************************************************/ void DBHandler:: InitializeAndEstablishConnection() { //Initialize the COM library. CoInitialize(NULL); //Obtain access to the SQLOLEDB provider. hr = CoCreateInstance( CLSID_OraOLEDB, NULL, CLSCTX_INPROC_SERVER, IID_IDBInitialize, (void **) &pIDBInitialize); if (FAILED(hr)) { AfxMessageBox("Failed in CoCreateInstance()"); DispErrorInfo(pIDBInitialize, IID_IDBInitialize); } /* Initialize the property values needed to establish the connection. */ for(i = 0; i < nInitProps; i++) VariantInit(&InitProperties[i].vValue); //Specify server name. InitProperties[0].dwPropertyID = DBPROP_INIT_DATASOURCE; InitProperties[0].vValue.vt = VT_BSTR; InitProperties[0].vValue.bstrVal = Datasource.AllocSysString(); InitProperties[0].dwOptions = DBPROPOPTIONS_REQUIRED; InitProperties[0].colid = DB_NULLID; //Specify level of prompting to be done InitProperties[1].dwPropertyID = DBPROP_INIT_PROMPT; InitProperties[1].vValue.vt = VT_I2; InitProperties[1].vValue.iVal = DBPROMPT_NOPROMPT; InitProperties[1].dwOptions = DBPROPOPTIONS_REQUIRED; InitProperties[1].colid = DB_NULLID; //Specify username (login). InitProperties[2].dwPropertyID = DBPROP_AUTH_USERID; InitProperties[2].vValue.vt = VT_BSTR; InitProperties[2].vValue.bstrVal=Username.AllocSysString(); InitProperties[2].dwOptions = DBPROPOPTIONS_REQUIRED; InitProperties[2].colid = DB_NULLID; //Specify password. InitProperties[3].dwPropertyID = DBPROP_AUTH_PASSWORD; InitProperties[3].vValue.vt = VT_BSTR; InitProperties[3].vValue.bstrVal = Password.AllocSysString(); InitProperties[3].dwOptions = DBPROPOPTIONS_REQUIRED; InitProperties[3].colid = DB_NULLID; /* Now that properties are set, construct the DBPROPSET structure (rgInitPropSet). The DBPROPSET structure is used to pass an array of DBPROP structures (InitProperties) to the SetProperties method. */ rgInitPropSet[0].guidPropertySet = DBPROPSET_DBINIT; rgInitPropSet[0].cProperties = 4; rgInitPropSet[0].rgProperties = InitProperties; //Set initialization properties. hr = pIDBInitialize->QueryInterface( IID_IDBProperties, (void **)&pIDBProperties); if (FAILED(hr)) { AfxMessageBox("Failed to obtain IDBProperties interface"); DispErrorInfo(pIDBInitialize, IID_IDBInitialize); } hr = pIDBProperties->SetProperties(nPropSet,rgInitPropSet); if(FAILED(hr)) { AfxMessageBox("Failed to set initialization properties."); DispErrorInfo(pIDBProperties, IID_IDBProperties); } pIDBProperties->Release(); //Now establish a connection to the data source. if(FAILED(pIDBInitialize->Initialize())) { AfxMessageBox("Problem in initializing."); DispErrorInfo(pIDBInitialize, IID_IDBInitialize); } } //end of InitializeAndEstablishConnection. /********************************************************************************** This function gets the product names and languages from database. Steps for retrieving data are as follows - 1.Specify the SQL select statement (passed as parameter to function) 2.Establish a connection to database and create a session 3.Create a command ,set command text and execute it. Get results in rowset pointer. 4.Determine the data (columns contained in rowset pointer) 5.Bind the data in each column to a consumer buffer specifying attributes of each column(like type,size,value etc) 6.Create an accessor using the column bindings in the consumer buffer 7.Return the rowset pointer containing data to calling function and get the actual data there ************************************************************************************/ IRowset* DBHandler::ExecuteQuery(CString p_sqlString) { cbColOffset=0; /***************************************** Make Connection and create session ******************************************/ //Establish connection to database InitializeAndEstablishConnection(); //Obtain a pointer of IDBCreateSession interface if(FAILED(pIDBInitialize->QueryInterface( IID_IDBCreateSession, (void**) &pIDBCreateSession))) { AfxMessageBox("Failed to get IDBCreateSession interface in ExecuteQuery()"); DispErrorInfo(pIDBInitialize, IID_IDBInitialize); } //Create a session with database if(FAILED(pIDBCreateSession->CreateSession( NULL, IID_IDBCreateCommand, (IUnknown**) &pIDBCreateCommand))) { AfxMessageBox("CreateSession failed in ExecuteQuery()"); DispErrorInfo(pIDBCreateSession, IID_IDBCreateSession); } //Release the pointer pIDBCreateSession->Release(); /******************************************************* Create and execute the command text *******************************************************/ //Create a command t