IConditionFactory::Resolve Method

  • Article

Performs a variety of transformations on a condition tree, including the following: resolves conditions with relative date/time expressions to conditions with absolute date/time (as a VT_FILETIME); turns other recognized named entities into condition trees with actual values; simplifies condition trees; replaces virtual or compound properties with OR trees of other properties; removes condition trees resulting from queries with property keywords that had no condition applied.

Syntax

HRESULT Resolve(      
    ICondition *pc,
    STRUCTURED_QUERY_RESOLVE_OPTION sqro,
    SYSTEMTIME const *pstReferenceTime,
    ICondition **ppcResolved
);

Parameters

  • pc
    [in] A pointer to an ICondition object to be resolved.
  • sqro
    [in] Specifies zero or more of the STRUCTURED_QUERY_RESOLVE_OPTION flags. For Windows 7 and later, the SQRO_ADD_VALUE_TYPE_FOR_PLAIN_VALUES flag is automatically added to sqro.
  • pstReferenceTime
    [in] A pointer to a SYSTEMTIME value to use as the reference date and time. A null pointer can be passed if sqro is set to SQRO_DONT_RESOLVE_DATETIME.
  • ppcResolved
    [out, retval] Receives a pointer to the new ICondition in which all time fields have been resolved to have values of type VT_FILETIME. This new condition tree is the resolved version of pc.

Return Value

Returns S_OK if successful, or an error value otherwise.

Remarks

In a condition tree produced by the IQueryParser::Parse method and returned by IQuerySolution::GetQuery, the leaves pair up properties with restrictions on these properties, and result in a condition tree that is partially finished. The IConditionFactory::Resolve method finishes such a condition tree by a process known as resolution. The input condition tree is not modified in any way. The output condition tree may share parts of the input condition that contained no leaf nodes with unresolved date/time values.

Note  Resolving a leaf node often produces a non-leaf node.

For example, Structured Query supports relative date/time expressions, which remain unresolved until they are applied to some reference time. In a leaf node with semantic type System.StructuredQueryType.DateTime, the value can be either a VT_FILETIME or a VT_LPWSTR. VT_FILETIME is an absolute date/time so it is already resolved. VT_LPWSTR is a string representation of a relative date/time expression. The specified reference time should be a local time, but the resolved times in the resulting query expression will be in coordinated universal time (UTC).

The StructuredQuerySample code sample, available on Code Gallery and the Windows 7 SDK, demonstrates how to read lines from the console, parse them using the system schema, and display the resulting condition trees.

See Also

IConditionFactory, CONDITION_TYPE, CONDITION_OPERATION, IConditionFactory2, ICondition, ICondition2