www.pudn.com > mitab.rar > ogrfeaturequery.cpp
/******************************************************************************
* $Id: ogrfeaturequery.cpp,v 1.9 2005/04/03 21:05:39 fwarmerdam Exp $
*
* Project: OpenGIS Simple Features Reference Implementation
* Purpose: Implementation of simple SQL WHERE style attributes queries
* for OGRFeatures.
* Author: Frank Warmerdam, warmerdam@pobox.com
*
******************************************************************************
* Copyright (c) 2001, Frank Warmerdam
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
******************************************************************************
*
* $Log: ogrfeaturequery.cpp,v $
* Revision 1.9 2005/04/03 21:05:39 fwarmerdam
* Fixed IN operator for Reals.
*
* Revision 1.8 2004/02/23 21:48:19 warmerda
* Fixed bug with support for IS NULL and IS NOT NULL on list fields.
* Added preliminary (untested) support for GetUsedFields().
*
* Revision 1.7 2003/03/04 05:46:31 warmerda
* added EvaluateAgainstIndices for OGRFeatureQuery
*
* Revision 1.6 2002/04/29 19:31:55 warmerda
* added support for FID field
*
* Revision 1.5 2002/04/19 20:46:06 warmerda
* added [NOT] IN, [NOT] LIKE and IS [NOT] NULL support
*
* Revision 1.4 2001/10/25 16:41:01 danmo
* Fixed OGRFeatureQueryEvaluator() crash with string fields with unset value
*
* Revision 1.3 2001/07/19 18:25:07 warmerda
* expanded tabs
*
* Revision 1.2 2001/07/18 05:03:05 warmerda
* added CPL_CVSID
*
* Revision 1.1 2001/06/19 15:46:41 warmerda
* New
*
*/
#include
#include "ogr_feature.h"
#include "ogr_p.h"
#include "ogrsf_frmts.h"
#include "ogr_attrind.h"
CPL_CVSID("$Id: ogrfeaturequery.cpp,v 1.9 2005/04/03 21:05:39 fwarmerdam Exp $");
CPL_C_START
#include "swq.h"
CPL_C_END
/************************************************************************/
/* OGRFeatureQuery() */
/************************************************************************/
OGRFeatureQuery::OGRFeatureQuery()
{
poTargetDefn = NULL;
pSWQExpr = NULL;
}
/************************************************************************/
/* ~OGRFeatureQuery() */
/************************************************************************/
OGRFeatureQuery::~OGRFeatureQuery()
{
if( pSWQExpr != NULL )
swq_expr_free( (swq_expr *) pSWQExpr );
}
/************************************************************************/
/* Parse */
/************************************************************************/
OGRErr OGRFeatureQuery::Compile( OGRFeatureDefn *poDefn,
const char * pszExpression )
{
/* -------------------------------------------------------------------- */
/* Clear any existing expression. */
/* -------------------------------------------------------------------- */
if( pSWQExpr != NULL )
swq_expr_free( (swq_expr *) pSWQExpr );
/* -------------------------------------------------------------------- */
/* Build list of fields. */
/* -------------------------------------------------------------------- */
char **papszFieldNames;
swq_field_type *paeFieldTypes;
int iField;
int nFieldCount = poDefn->GetFieldCount()+1;
papszFieldNames = (char **)
CPLMalloc(sizeof(char *) * nFieldCount );
paeFieldTypes = (swq_field_type *)
CPLMalloc(sizeof(swq_field_type) * nFieldCount );
for( iField = 0; iField < poDefn->GetFieldCount(); iField++ )
{
OGRFieldDefn *poField = poDefn->GetFieldDefn( iField );
papszFieldNames[iField] = (char *) poField->GetNameRef();
switch( poField->GetType() )
{
case OFTInteger:
paeFieldTypes[iField] = SWQ_INTEGER;
break;
case OFTReal:
paeFieldTypes[iField] = SWQ_FLOAT;
break;
case OFTString:
paeFieldTypes[iField] = SWQ_STRING;
break;
default:
paeFieldTypes[iField] = SWQ_OTHER;
break;
}
}
papszFieldNames[nFieldCount-1] = "FID";
paeFieldTypes[nFieldCount-1] = SWQ_INTEGER;
/* -------------------------------------------------------------------- */
/* Try to parse. */
/* -------------------------------------------------------------------- */
const char *pszError;
OGRErr eErr = OGRERR_NONE;
poTargetDefn = poDefn;
pszError = swq_expr_compile( pszExpression, nFieldCount,
papszFieldNames, paeFieldTypes,
(swq_expr **) &pSWQExpr );
if( pszError != NULL )
{
CPLError( CE_Failure, CPLE_AppDefined,
"%s", pszError );
eErr = OGRERR_CORRUPT_DATA;
pSWQExpr = NULL;
}
CPLFree( papszFieldNames );
CPLFree( paeFieldTypes );
return eErr;
}
/************************************************************************/
/* OGRFeatureQueryEvaluator() */
/************************************************************************/
static int OGRFeatureQueryEvaluator( swq_field_op *op, OGRFeature *poFeature )
{
OGRField sFID;
OGRField *psField;
if( op->field_index == poFeature->GetDefnRef()->GetFieldCount() )
{
sFID.Integer = poFeature->GetFID();
psField = &sFID;
}
else
psField = poFeature->GetRawFieldRef( op->field_index );
switch( op->field_type )
{
case SWQ_INTEGER:
switch( op->operation )
{
case SWQ_EQ:
return psField->Integer == op->int_value;
case SWQ_NE:
return psField->Integer != op->int_value;
case SWQ_LT:
return psField->Integer < op->int_value;
case SWQ_GT:
return psField->Integer > op->int_value;
case SWQ_LE:
return psField->Integer <= op->int_value;
case SWQ_GE:
return psField->Integer >= op->int_value;
case SWQ_ISNULL:
return !poFeature->IsFieldSet( op->field_index );
case SWQ_IN:
{
const char *pszSrc;
pszSrc = op->string_value;
while( *pszSrc != '\0' )
{
if( atoi(pszSrc) == psField->Integer )
return TRUE;
pszSrc += strlen(pszSrc) + 1;
}
return FALSE;
}
default:
CPLDebug( "OGRFeatureQuery",
"Illegal operation (%d) on integer field.",
op->operation );
return FALSE;
}
case SWQ_FLOAT:
switch( op->operation )
{
case SWQ_EQ:
return psField->Real == op->float_value;
case SWQ_NE:
return psField->Real != op->float_value;
case SWQ_LT:
return psField->Real < op->float_value;
case SWQ_GT:
return psField->Real > op->float_value;
case SWQ_LE:
return psField->Real <= op->float_value;
case SWQ_GE:
return psField->Real >= op->float_value;
case SWQ_ISNULL:
return !poFeature->IsFieldSet( op->field_index );
case SWQ_IN:
{
const char *pszSrc;
pszSrc = op->string_value;
while( *pszSrc != '\0' )
{
if( atof(pszSrc) == psField->Real )
return TRUE;
pszSrc += strlen(pszSrc) + 1;
}
return FALSE;
}
default:
CPLDebug( "OGRFeatureQuery",
"Illegal operation (%d) on float field.",
op->operation );
return FALSE;
}
case SWQ_STRING:
switch( op->operation )
{
case SWQ_EQ:
if (psField->Set.nMarker1 == OGRUnsetMarker
&& psField->Set.nMarker2 == OGRUnsetMarker )
{
return (op->string_value[0] == '\0');
}
else
{
return EQUAL(psField->String,op->string_value);
}
case SWQ_NE:
if (psField->Set.nMarker1 == OGRUnsetMarker
&& psField->Set.nMarker2 == OGRUnsetMarker )
{
return (op->string_value[0] != '\0');
}
else
{
return !EQUAL(psField->String,op->string_value);
}
case SWQ_ISNULL:
return !poFeature->IsFieldSet( op->field_index );
case SWQ_LIKE:
if (psField->Set.nMarker1 != OGRUnsetMarker
|| psField->Set.nMarker2 != OGRUnsetMarker )
return swq_test_like(psField->String, op->string_value);
else
return FALSE;
case SWQ_IN:
{
const char *pszSrc;
if( !poFeature->IsFieldSet(op->field_index) )
return FALSE;
pszSrc = op->string_value;
while( *pszSrc != '\0' )
{
if( EQUAL(pszSrc,psField->String) )
return TRUE;
pszSrc += strlen(pszSrc) + 1;
}
return FALSE;
}
default:
CPLDebug( "OGRFeatureQuery",
"Illegal operation (%d) on string field.",
op->operation );
return FALSE;
}
case SWQ_OTHER:
switch( op->operation )
{
case SWQ_ISNULL:
return !poFeature->IsFieldSet( op->field_index );
default:
CPLDebug( "OGRFeatureQuery",
"Illegal operation (%d) on list or binary field.",
op->operation );
return FALSE;
}
default:
assert( FALSE );
return FALSE;
}
}
/************************************************************************/
/* Evaluate() */
/************************************************************************/
int OGRFeatureQuery::Evaluate( OGRFeature *poFeature )
{
if( pSWQExpr == NULL )
return FALSE;
return swq_expr_evaluate( (swq_expr *) pSWQExpr,
(swq_op_evaluator) OGRFeatureQueryEvaluator,
(void *) poFeature );
}
/************************************************************************/
/* EvaluateAgainstIndices() */
/* */
/* Attempt to return a list of FIDs matching the given */
/* attribute query conditions utilizing attribute indices. */
/* Returns NULL if the result cannot be computed from the */
/* available indices, or an "OGRNullFID" terminated list of */
/* FIDs if it can. */
/* */
/* For now we only support equality tests on a single indexed */
/* attribute field. Eventually we should make this support */
/* multi-part queries with ranges. */
/************************************************************************/
long *OGRFeatureQuery::EvaluateAgainstIndices( OGRLayer *poLayer,
OGRErr *peErr )
{
swq_expr *psExpr = (swq_expr *) pSWQExpr;
OGRAttrIndex *poIndex;
if( peErr != NULL )
*peErr = OGRERR_NONE;
/* -------------------------------------------------------------------- */
/* Does the expression meet our requirements? Do we have an */
/* index on the targetted field? */
/* -------------------------------------------------------------------- */
if( psExpr == NULL || psExpr->operation != SWQ_EQ
|| poLayer->GetIndex() == NULL )
return NULL;
poIndex = poLayer->GetIndex()->GetFieldIndex( psExpr->field_index );
if( poIndex == NULL )
return NULL;
/* -------------------------------------------------------------------- */
/* OK, we have an index, now we need to query it. */
/* -------------------------------------------------------------------- */
OGRField sValue;
OGRFieldDefn *poFieldDefn;
poFieldDefn = poLayer->GetLayerDefn()->GetFieldDefn(psExpr->field_index);
switch( poFieldDefn->GetType() )
{
case OFTInteger:
sValue.Integer = psExpr->int_value;
break;
case OFTReal:
sValue.Real = psExpr->float_value;
break;
case OFTString:
sValue.String = psExpr->string_value;
break;
default:
CPLAssert( FALSE );
return NULL;
}
return poIndex->GetAllMatches( &sValue );
}
/************************************************************************/
/* OGRFieldCollector() */
/* */
/* Helper function for recursing through tree to satisfy */
/* GetUsedFields(). */
/************************************************************************/
char **OGRFeatureQuery::FieldCollector( void *pBareOp,
char **papszList )
{
swq_field_op *op = (swq_field_op *) pBareOp;
/* -------------------------------------------------------------------- */
/* References to tables other than the primarily are currently */
/* unsupported. Error out. */
/* -------------------------------------------------------------------- */
if( op->table_index != 0 )
{
CSLDestroy( papszList );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Add the field name into our list if it is not already there. */
/* -------------------------------------------------------------------- */
const char *pszFieldName;
if( op->field_index == poTargetDefn->GetFieldCount() )
pszFieldName = "FID";
else if( op->field_index >= 0
&& op->field_index < poTargetDefn->GetFieldCount() )
pszFieldName =
poTargetDefn->GetFieldDefn(op->field_index)->GetNameRef();
else
{
CSLDestroy( papszList );
return NULL;
}
if( CSLFindString( papszList, pszFieldName ) == -1 )
papszList = CSLAddString( papszList, pszFieldName );
/* -------------------------------------------------------------------- */
/* Add in fields from subexpressions. */
/* -------------------------------------------------------------------- */
if( op->first_sub_expr != NULL )
papszList = FieldCollector( op->first_sub_expr, papszList );
if( op->second_sub_expr != NULL )
papszList = FieldCollector( op->second_sub_expr, papszList );
return papszList;
}
/************************************************************************/
/* 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 succesful
* use, no non-empty expression should return an empty list.
*
* @return list of field names. Free list with CSLDestroy() when no longer
* required.
*/
char **OGRFeatureQuery::GetUsedFields( )
{
if( pSWQExpr == NULL )
return NULL;
return FieldCollector( pSWQExpr, NULL );
}