Structured Query Code Sample
This page contains a code sample to outline how to use various interfaces and methods exposed by StructuredQuery.h. This sample is available for download with the Windows Vista SDK.
Notes and includes
THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright (c) Microsoft Corporation. All rights reserved.
Link this against sdk\lib\StructuredQuery.lib.
This sample program reads lines from the console, parses them using the system schema, and displays the resulting condition trees. A real application might feed the condition trees to a graphical UI and/or translate them into a query language to be executed.
#include <stdio.h> #include <StructuredQuery.h>
GetLabel
Return a label for a condition operation. Do not free the result. This is used in the DisplayQuery function below.
PCWSTR GetLabel(CONDITION_OPERATION cop)
{
PCWSTR pszOperation;
switch (cop)
{
case COP_IMPLICIT:
pszOperation = L"IMPLICIT";
break;
case COP_EQUAL:
pszOperation = L"=";
break;
case COP_NOTEQUAL:
pszOperation = L"!=";
break;
case COP_LESSTHAN:
pszOperation = L"<";
break;
case COP_GREATERTHAN:
pszOperation = L">";
break;
case COP_LESSTHANOREQUAL:
pszOperation = L"<=";
break;
case COP_GREATERTHANOREQUAL:
pszOperation = L">=";
break;
case COP_VALUE_STARTSWITH:
pszOperation = L"VALUE_STARTS_WITH";
break;
case COP_VALUE_ENDSWITH:
pszOperation = L"VALUE_ENDS_WITH";
break;
case COP_VALUE_CONTAINS:
pszOperation = L"VALUE_CONTAINS";
break;
case COP_VALUE_NOTCONTAINS:
pszOperation = L"VALUE_DOES_NOT_CONTAIN";
break;
case COP_DOSWILDCARDS:
pszOperation = L"MATCHES";
break;
case COP_WORD_EQUAL:
pszOperation = L"CONTAINS_WORD";
break;
case COP_WORD_STARTSWITH:
pszOperation = L"CONTAINS_WORD_STARTING_WITH";
break;
case COP_APPLICATION_SPECIFIC:
pszOperation = L"APPLICATION_SPECIFIC";
break;
default:
pszOperation = L"???";
break;
}
return pszOperation;
}
DisplayQuery
Display one condition tree, with indentation.
HRESULT DisplayQuery(__in ICondition* pCondition, __in LONG lIndent)
{
CONDITION_TYPE ct;
HRESULT hr = pCondition->GetConditionType(&ct);
if (SUCCEEDED(hr))
{
switch (ct)
{
case CT_AND_CONDITION:
case CT_OR_CONDITION:
{
wprintf(L"%*s%s\n", 2*lIndent, L"", (ct == CT_AND_CONDITION ? L"AND" : L"OR"));
IEnumUnknown* peuSubs;
hr = pCondition->GetSubConditions(IID_PPV_ARGS(&peuSubs));
if (SUCCEEDED(hr))
{
IUnknown* punk;
while ((hr = peuSubs->Next(1, &punk, NULL)) == S_OK)
{
ICondition* pSubCondition;
hr = punk->QueryInterface(IID_PPV_ARGS(&pSubCondition));
if(SUCCEEDED(hr))
{
DisplayQuery(pSubCondition, lIndent+1);
pSubCondition->Release();
}
punk->Release();
}
peuSubs->Release();
}
}
break;
case CT_NOT_CONDITION:
{
wprintf(L"%*s%s\n", 2*lIndent, L"", L"NOT");
// ICondition::GetSubConditions can return the single subcondition of
// a negation node directly.
ICondition* pSubCondition;
hr = pCondition->GetSubConditions(IID_PPV_ARGS(&pSubCondition));
if (SUCCEEDED(hr))
{
DisplayQuery(pSubCondition, lIndent+1);
pSubCondition->Release();
}
}
break;
case CT_LEAF_CONDITION:
{
PWSTR pszPropertyName;
CONDITION_OPERATION cop;
PROPVARIANT propvar;
hr = pCondition->GetComparisonInfo(&pszPropertyName, &cop, &propvar);
if (SUCCEEDED(hr))
{
PWSTR pszNormalizedValue;
hr = pCondition->GetValueNormalization(&pszNormalizedValue);
if (SUCCEEDED(hr))
{
PWSTR pszSemanticType;
hr = pCondition->GetValueType(&pszSemanticType);
if (SUCCEEDED(hr))
{
// It is permitted to have a leaf condition with null semantic type,
// so let us guard against that.
if (!pszSemanticType)
{
pszSemanticType = (WCHAR*)CoTaskMemAlloc(4 * sizeof WCHAR);
pszSemanticType[0] = pszSemanticType[1] = pszSemanticType[2] = L'?';
pszSemanticType[3] = L'\0';
}
wprintf(L"%*sLEAF %s %s %s (%s)\n", 2*lIndent, L"", pszPropertyName, GetLabel(cop), pszNormalizedValue, pszSemanticType);
CoTaskMemFree(pszSemanticType);
}
CoTaskMemFree(pszNormalizedValue);
}
CoTaskMemFree(pszPropertyName);
(void) PropVariantClear(&propvar);
}
}
break;
}
}
return hr;
}
wMain
Main module.
int __cdecl wmain(__in int argc, __in_ecount(argc) WCHAR const* argv[])
{
HRESULT hr;
if (argc > 1)
{
wprintf(L"Usage: StructuredQuerySample1.exe\n\tThen enter queries to be parsed, one per line.\n\tAn empty line terminates the program.\n");
hr = E_INVALIDARG;
}
else
{
hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
if (SUCCEEDED(hr))
{
// It is possible to CoCreateInstance a query parser directly using __uuidof(QueryParser) but by
// using a QueryParserManager we can get a query parser prepared for a certain language and catalog.
IQueryParserManager* pQueryParserManager;
hr = CoCreateInstance(__uuidof(QueryParserManager), NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pQueryParserManager));
if (SUCCEEDED(hr))
{
// The locale given to IQueryParserManager::CreateLoadedParser should be the user interface locale of the
// application, which is usually the same as the operating system's locale for this user. It is used for
// deciding what language to be used when interpreting keywords.
IQueryParser* pQueryparser;
hr = pQueryParserManager->CreateLoadedParser(L"SystemIndex", LOCALE_USER_DEFAULT, IID_PPV_ARGS(&pQueryparser));
if (SUCCEEDED(hr))
{
// This sample turns on "natural query syntax", which is the more relaxed and human language like
// search notation, and also makes searches automatically look for words beginning with what has been
// specified (so an input of "from bill" will search for anything from someone whose name beginns with
// "bill".
hr = pQueryParserManager->InitializeOptions(TRUE, TRUE, pQueryparser);
if (SUCCEEDED(hr))
{
WCHAR szLine[1024];
while (fgetws(szLine, ARRAYSIZE(szLine), stdin)[0] != L'\n')
{
// The actual work of parsing a query string is done here.
IQuerySolution* pQuerySolution;
hr = pQueryparser->Parse(szLine, NULL, &pQuerySolution);
if (SUCCEEDED(hr))
{
// In this sample we do not bother distinguishing between various
// parse errors though we could. Note that there will be a solution
// even though there were parse errors; it just may not be what the
// user intended.
IEnumUnknown* peu;
hr = pQuerySolution->GetErrors(IID_PPV_ARGS(&peu));
if (SUCCEEDED(hr))
{
if (peu->Skip(1) == S_OK)
{
wprintf(L"Some part of the query string could not be parsed.\n");
}
ICondition* pCondition;
hr = pQuerySolution->GetQuery(&pCondition, NULL);
if (SUCCEEDED(hr))
{
// IQuerySolution::Resolve turns any relative time references (like
// "today") into absolute time references (in the UTC time zone),
// and also simplifies the result in various ways. Note that
// pCondition is unchanged and can be resolved against additional
// dates/times.
SYSTEMTIME st;
GetLocalTime(&st);
ICondition* pConditionResolved;
hr = pQuerySolution->Resolve(pCondition, 0, &st, &pConditionResolved);
if (SUCCEEDED(hr))
{
hr = DisplayQuery(pConditionResolved, 0);
pConditionResolved->Release();
}
pCondition->Release();
}
peu->Release();
}
pQuerySolution->Release();
}
}
}
pQueryparser->Release();
}
pQueryParserManager->Release();
}
CoUninitialize();
}
}
return SUCCEEDED(hr) ? EXIT_SUCCESS : EXIT_FAILURE;}
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