Question

我要搜索的行取决于我的Blob列的值。

我已经尝试过此代码

HRESULT hres;

// Step 1: --------------------------------------------------
// Initialize COM. ------------------------------------------

hres = CoInitializeEx(0, COINIT_MULTITHREADED);
if (FAILED(hres)) { return 1; }

// Step 2: --------------------------------------------------
// Set general COM security levels --------------------------

hres = CoInitializeSecurity(nullptr, -1, nullptr, nullptr, RPC_C_AUTHN_LEVEL_DEFAULT, RPC_C_IMP_LEVEL_IMPERSONATE,
    nullptr, EOAC_NONE, nullptr);
if (FAILED(hres)) { return 1; }

// Step 3: ---------------------------------------------------
// Obtain the initial locator to WMI -------------------------
IWbemLocator *pLoc = nullptr;
hres = CoCreateInstance(CLSID_WbemLocator, nullptr, CLSCTX_INPROC_SERVER, IID_IWbemLocator, reinterpret_cast<LPVOID *>(&pLoc));
if (FAILED(hres)) { return 1; }

// Step 4: -----------------------------------------------------
// Connect to WMI through the IWbemLocator::ConnectServer method

IWbemServices *pSvc = nullptr;

// Connect to the root\cimv2 namespace with
// the current user and obtain pointer pSvc
// to make IWbemServices calls.
hres = pLoc->ConnectServer(_bstr_t(L"ROOT\\CIMV2"), nullptr, nullptr, nullptr, NULL, nullptr, nullptr, &pSvc);

if (FAILED(hres)) { pLoc->Release();        CoUninitialize();        return 1; }


// Step 5: --------------------------------------------------
// Set security levels on the proxy -------------------------

hres = CoSetProxyBlanket(pSvc, RPC_C_AUTHN_WINNT, RPC_C_AUTHZ_NONE, nullptr,
    RPC_C_AUTHN_LEVEL_CALL, RPC_C_IMP_LEVEL_IMPERSONATE, nullptr, EOAC_NONE);

if (FAILED(hres)) { pSvc->Release();        pLoc->Release();        CoUninitialize();        return 1; }

// Step 6: --------------------------------------------------
// Use the IWbemServices pointer to make requests of WMI ----

// For example, get the name of the operating system
IEnumWbemClassObject* pEnumerator = nullptr;
hres = pSvc->ExecQuery(
    bstr_t("WQL"),
    bstr_t("SELECT * FROM Win32_ComputerSystemProduct"),
    WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
    nullptr,
    &pEnumerator);

if (FAILED(hres)) { pSvc->Release(); pLoc->Release(); CoUninitialize(); return 1; }

// Step 7: -------------------------------------------------
// Get the data from the query in step 6 -------------------

IWbemClassObject *pclsObj = nullptr;
ULONG uReturn = 0;

HRESULT hr = pEnumerator->Next(WBEM_INFINITE, 1, &pclsObj, &uReturn);
VARIANT vtProp;

// Get the value of the Name property
hr = pclsObj->Get(L"UUID", 0, &vtProp, 0, 0);
wcout << " OS Name : " << vtProp.bstrVal << endl;
VariantClear(&vtProp);

pclsObj->Release();

// Cleanup
// ========

pSvc->Release();
pLoc->Release();
pEnumerator->Release();
CoUninitialize();

return 0;

但是它根本不起作用。谁能告诉我我的代码有什么问题吗？谢谢。

MySQL按blob值搜索行

0 个答案: