开始之前,需要知道的一些不属于OLE DB,但又需要用道的函数。
CoInitialize();
CoCreateInstance();
创建一个单一的,由CLSID指定的未初始化的类对象。
STDAPI CoCreateInstance(
REECLSID rclsid, //Class identifier (CLSID) of the object
LPUNKNOWN pUnkOuter, //Pointer to controlling IUnknow
DWORD dwClsContext, //Context for running executable code
REFIID riid, //Reference to the identifier of the interface
LPVOID * ppv //Address of output variable that receives
);
REFCLSID rclsid,
REFIID riid,
两个id指定了组件及其接口。
DWORD dwClsContext = CLSCTX_INPROC_SERVER,
IDBPromptInitialize* pIDBPromptInitialize;
hr = CoCreateInstance(
CLSID_DataLinks,
NULL,
CLSCTX_INPROC_SERVER,
IID_IDBPromptInitialize,
(void**)&pIDBPromptInitialize);
CoGetMalloc();
CoUninitialize();
包含的头文件:
#include <oledb.h>
#include <oledberr.h>
#include <msdasc.h>
#include <comdef.h>
#include "jetoledb.h"
#include "msjetoledb.h"