OGRFeatureQuery Class Reference

Public Member Functions
OGRErr	Compile (OGRFeatureDefn *, const char *, int bCheck=TRUE, swq_custom_func_registrar *poCustomFuncRegistrar=NULL)
int	Evaluate (OGRFeature *)
GIntBig *	EvaluateAgainstIndices (OGRLayer *, OGRErr *)
int	CanUseIndex (OGRLayer *)
char **	GetUsedFields ()
	Returns lists of fields in expression. More...
void *	GetSWQExpr ()

Member Function Documentation

GetUsedFields()

char ** OGRFeatureQuery::GetUsedFields

(

)

Returns lists of fields in expression.

All attribute fields are used in the expression of this feature query are returned as a StringList of field names. This function would primarily be used within drivers to recognise special case conditions depending only on attribute fields that can be very efficiently fetched.

NOTE: If any fields in the expression are from tables other than the primary table then NULL is returned indicating an error. In successful use, no non-empty expression should return an empty list.

Returns

list of field names. Free list with CSLDestroy() when no longer required.

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The documentation for this class was generated from the following files:

• ogr_feature.h
• ogrfeaturequery.cpp