void QgsMssqlFeatureIterator::BuildStatement( const QgsFeatureRequest& request ) { // build sql statement mStatement = QString( "select " ); int fieldCount = 0; mFidCol = -1; mGeometryCol = -1; if ( !request.subsetOfAttributes().empty() ) { // subset of attributes has been specified for ( QgsAttributeList::const_iterator it = request.subsetOfAttributes().begin(); it != request.subsetOfAttributes().end(); ++it ) { if ( fieldCount != 0 ) mStatement += ","; mStatement += "[" + mSource->mFields[*it].name() + "]"; if ( !mSource->mFidColName.isEmpty() && mSource->mFidColName == mSource->mFields[*it].name() ) mFidCol = fieldCount; ++fieldCount; mAttributesToFetch.append( *it ); } } else { // get all attributes for ( int i = 0; i < mSource->mFields.count(); i++ ) { if ( fieldCount != 0 ) mStatement += ","; mStatement += "[" + mSource->mFields[i].name() + "]"; if ( !mSource->mFidColName.isEmpty() && mSource->mFidColName == mSource->mFields[i].name() ) mFidCol = fieldCount; ++fieldCount; mAttributesToFetch.append( i ); } } // get fid col if not yet required if ( mFidCol == -1 && !mSource->mFidColName.isEmpty() ) { if ( fieldCount != 0 ) mStatement += ","; mStatement += "[" + mSource->mFidColName + "]"; mFidCol = fieldCount; ++fieldCount; } // get geometry col if ( !( request.flags() & QgsFeatureRequest::NoGeometry ) && !mSource->mGeometryColName.isEmpty() ) { if ( fieldCount != 0 ) mStatement += ","; mStatement += "[" + mSource->mGeometryColName + "]"; mGeometryCol = fieldCount; ++fieldCount; } mStatement += " from "; if ( !mSource->mSchemaName.isEmpty() ) mStatement += "[" + mSource->mSchemaName + "]."; mStatement += "[" + mSource->mTableName + "]"; bool filterAdded = false; // set spatial filter if ( request.filterType() & QgsFeatureRequest::FilterRect ) { // polygons should be CCW for SqlGeography QString r; QTextStream foo( &r ); foo.setRealNumberPrecision( 8 ); foo.setRealNumberNotation( QTextStream::FixedNotation ); foo << request.filterRect().xMinimum() << " " << request.filterRect().yMinimum() << ", " << request.filterRect().xMaximum() << " " << request.filterRect().yMinimum() << ", " << request.filterRect().xMaximum() << " " << request.filterRect().yMaximum() << ", " << request.filterRect().xMinimum() << " " << request.filterRect().yMaximum() << ", " << request.filterRect().xMinimum() << " " << request.filterRect().yMinimum(); mStatement += QString( " where [%1].STIntersects([%2]::STGeomFromText('POLYGON((%3))',%4)) = 1" ).arg( mSource->mGeometryColName, mSource->mGeometryColType, r, QString::number( mSource->mSRId ) ); filterAdded = true; } // set fid filter if (( request.filterType() & QgsFeatureRequest::FilterFid ) && !mSource->mFidColName.isEmpty() ) { // set attribute filter if ( !filterAdded ) mStatement += QString( " where [%1] = %2" ).arg( mSource->mFidColName, QString::number( request.filterFid() ) ); else mStatement += QString( " and [%1] = %2" ).arg( mSource->mFidColName, QString::number( request.filterFid() ) ); filterAdded = true; } if ( !mSource->mSqlWhereClause.isEmpty() ) { if ( !filterAdded ) mStatement += " where (" + mSource->mSqlWhereClause + ")"; else mStatement += " and (" + mSource->mSqlWhereClause + ")"; } if ( fieldCount == 0 ) { QgsDebugMsg( "QgsMssqlProvider::select no fields have been requested" ); mStatement.clear(); } }
QgsVirtualLayerFeatureIterator::QgsVirtualLayerFeatureIterator( QgsVirtualLayerFeatureSource *source, bool ownSource, const QgsFeatureRequest &request ) : QgsAbstractFeatureIteratorFromSource<QgsVirtualLayerFeatureSource>( source, ownSource, request ) { // NOTE: this is really bad and should be removed. // it's only here to guard mSource->mSqlite - because if the provider is removed // then mSqlite will be meaningless. // this needs to be totally reworked so that mSqlite no longer depends on the provider // and can be fully encapsulated in the source if ( !mSource->mProvider ) { close(); return; } if ( mRequest.destinationCrs().isValid() && mRequest.destinationCrs() != mSource->mCrs ) { mTransform = QgsCoordinateTransform( mSource->mCrs, mRequest.destinationCrs(), mRequest.transformContext() ); } try { mFilterRect = filterRectToSourceCrs( mTransform ); } catch ( QgsCsException & ) { // can't reproject mFilterRect close(); return; } try { QString tableName = mSource->mTableName; QStringList wheres; QString offset; QString subset = mSource->mSubset; if ( !subset.isEmpty() ) { wheres << subset; } if ( !mSource->mDefinition.uid().isNull() ) { // filters are only available when a column with unique id exists if ( mSource->mDefinition.hasDefinedGeometry() && !mFilterRect.isNull() ) { bool do_exact = request.flags() & QgsFeatureRequest::ExactIntersect; QString mbr = QStringLiteral( "%1,%2,%3,%4" ).arg( mFilterRect.xMinimum() ).arg( mFilterRect.yMinimum() ).arg( mFilterRect.xMaximum() ).arg( mFilterRect.yMaximum() ); wheres << quotedColumn( mSource->mDefinition.geometryField() ) + " is not null"; wheres << QStringLiteral( "%1Intersects(%2,BuildMbr(%3))" ) .arg( do_exact ? "" : "Mbr", quotedColumn( mSource->mDefinition.geometryField() ), mbr ); } else if ( request.filterType() == QgsFeatureRequest::FilterFid ) { wheres << QStringLiteral( "%1=%2" ) .arg( quotedColumn( mSource->mDefinition.uid() ) ) .arg( request.filterFid() ); } else if ( request.filterType() == QgsFeatureRequest::FilterFids ) { QString values = quotedColumn( mSource->mDefinition.uid() ) + " IN ("; bool first = true; const auto constFilterFids = request.filterFids(); for ( QgsFeatureId v : constFilterFids ) { if ( !first ) { values += QLatin1String( "," ); } first = false; values += QString::number( v ); } values += QLatin1String( ")" ); wheres << values; } } else { if ( request.filterType() == QgsFeatureRequest::FilterFid ) { if ( request.filterFid() >= 0 ) offset = QStringLiteral( " LIMIT 1 OFFSET %1" ).arg( request.filterFid() ); else // never return a feature if the id is negative offset = QStringLiteral( " LIMIT 0" ); } else if ( !mFilterRect.isNull() && mRequest.flags() & QgsFeatureRequest::ExactIntersect ) { // if an exact intersection is requested, prepare the geometry to intersect QgsGeometry rectGeom = QgsGeometry::fromRect( mFilterRect ); mRectEngine.reset( QgsGeometry::createGeometryEngine( rectGeom.constGet() ) ); mRectEngine->prepareGeometry(); } } if ( request.flags() & QgsFeatureRequest::SubsetOfAttributes ) { // copy only selected fields const auto subsetOfAttributes = request.subsetOfAttributes(); for ( int idx : subsetOfAttributes ) { mAttributes << idx; } // ensure that all attributes required for expression filter are being fetched if ( request.filterType() == QgsFeatureRequest::FilterExpression ) { const auto constReferencedColumns = request.filterExpression()->referencedColumns(); for ( const QString &field : constReferencedColumns ) { int attrIdx = mSource->mFields.lookupField( field ); if ( !mAttributes.contains( attrIdx ) ) mAttributes << attrIdx; } } // also need attributes required by order by if ( mRequest.flags() & QgsFeatureRequest::SubsetOfAttributes && !mRequest.orderBy().isEmpty() ) { const auto usedAttributeIndices = mRequest.orderBy().usedAttributeIndices( mSource->mFields ); for ( int attrIdx : usedAttributeIndices ) { if ( !mAttributes.contains( attrIdx ) ) mAttributes << attrIdx; } } } else { mAttributes = mSource->mFields.allAttributesList(); } QString columns; { // the first column is always the uid (or 0) if ( !mSource->mDefinition.uid().isNull() ) { columns = quotedColumn( mSource->mDefinition.uid() ); } else { if ( request.filterType() == QgsFeatureRequest::FilterFid ) { columns = QString::number( request.filterFid() ); } else { columns = QStringLiteral( "0" ); } } const auto constMAttributes = mAttributes; for ( int i : constMAttributes ) { columns += QLatin1String( "," ); QString cname = mSource->mFields.at( i ).name().toLower(); columns += quotedColumn( cname ); } } // the last column is the geometry, if any if ( ( !( request.flags() & QgsFeatureRequest::NoGeometry ) || ( request.filterType() == QgsFeatureRequest::FilterExpression && request.filterExpression()->needsGeometry() ) ) && !mSource->mDefinition.geometryField().isNull() && mSource->mDefinition.geometryField() != QLatin1String( "*no*" ) ) { columns += "," + quotedColumn( mSource->mDefinition.geometryField() ); } mSqlQuery = "SELECT " + columns + " FROM " + tableName; if ( !wheres.isEmpty() ) { mSqlQuery += " WHERE " + wheres.join( QStringLiteral( " AND " ) ); } if ( !offset.isEmpty() ) { mSqlQuery += offset; } mQuery.reset( new Sqlite::Query( mSource->mSqlite, mSqlQuery ) ); mFid = 0; } catch ( std::runtime_error &e ) { QgsMessageLog::logMessage( e.what(), QObject::tr( "VLayer" ) ); close(); } }
QgsDelimitedTextFeatureIterator::QgsDelimitedTextFeatureIterator( QgsDelimitedTextFeatureSource *source, bool ownSource, const QgsFeatureRequest &request ) : QgsAbstractFeatureIteratorFromSource<QgsDelimitedTextFeatureSource>( source, ownSource, request ) , mTestSubset( mSource->mSubsetExpression ) { // Determine mode to use based on request... QgsDebugMsg( "Setting up QgsDelimitedTextIterator" ); // Does the layer have geometry - will revise later to determine if we actually need to // load it. bool hasGeometry = mSource->mGeomRep != QgsDelimitedTextProvider::GeomNone; if ( mRequest.destinationCrs().isValid() && mRequest.destinationCrs() != mSource->mCrs ) { mTransform = QgsCoordinateTransform( mSource->mCrs, mRequest.destinationCrs() ); } try { mFilterRect = filterRectToSourceCrs( mTransform ); } catch ( QgsCsException & ) { // can't reproject mFilterRect mClosed = true; return; } if ( !mFilterRect.isNull() && hasGeometry ) { QgsDebugMsg( "Configuring for rectangle select" ); mTestGeometry = true; // Exact intersection test only applies for WKT geometries mTestGeometryExact = mRequest.flags() & QgsFeatureRequest::ExactIntersect && mSource->mGeomRep == QgsDelimitedTextProvider::GeomAsWkt; // If request doesn't overlap extents, then nothing to return if ( ! mFilterRect.intersects( mSource->mExtent ) && !mTestSubset ) { QgsDebugMsg( "Rectangle outside layer extents - no features to return" ); mMode = FeatureIds; } // If the request extents include the entire layer, then revert to // a file scan else if ( mFilterRect.contains( mSource->mExtent ) && !mTestSubset ) { QgsDebugMsg( "Rectangle contains layer extents - bypass spatial filter" ); mTestGeometry = false; } // If we have a spatial index then use it. The spatial index already accounts // for the subset. Also means we don't have to test geometries unless doing exact // intersection else if ( mSource->mUseSpatialIndex ) { mFeatureIds = mSource->mSpatialIndex->intersects( mFilterRect ); // Sort for efficient sequential retrieval std::sort( mFeatureIds.begin(), mFeatureIds.end() ); QgsDebugMsg( QString( "Layer has spatial index - selected %1 features from index" ).arg( mFeatureIds.size() ) ); mMode = FeatureIds; mTestSubset = false; mTestGeometry = mTestGeometryExact; } } if ( request.filterType() == QgsFeatureRequest::FilterFid ) { QgsDebugMsg( "Configuring for returning single id" ); if ( mFilterRect.isNull() || mFeatureIds.contains( request.filterFid() ) ) { mFeatureIds = QList<QgsFeatureId>() << request.filterFid(); } mMode = FeatureIds; mTestSubset = false; } // If have geometry and testing geometry then evaluate options... // If we don't have geometry then all records pass geometry filter. // CC: 2013-05-09 // Not sure about intended relationship between filtering on geometry and // requesting no geometry? Have preserved current logic of ignoring spatial filter // if not requesting geometry. else // If we have a subset index then use it.. if ( mMode == FileScan && mSource->mUseSubsetIndex ) { QgsDebugMsg( QString( "Layer has subset index - use %1 items from subset index" ).arg( mSource->mSubsetIndex.size() ) ); mTestSubset = false; mMode = SubsetIndex; } // Otherwise just have to scan the file if ( mMode == FileScan ) { QgsDebugMsg( "File will be scanned for desired features" ); } // If the layer has geometry, do we really need to load it? // We need it if it is asked for explicitly in the request, // if we are testing geometry (ie spatial filter), or // if testing the subset expression. if ( hasGeometry && ( !( mRequest.flags() & QgsFeatureRequest::NoGeometry ) || mTestGeometry || ( mTestSubset && mSource->mSubsetExpression->needsGeometry() ) || ( request.filterType() == QgsFeatureRequest::FilterExpression && request.filterExpression()->needsGeometry() ) ) ) { mLoadGeometry = true; } else { QgsDebugMsgLevel( "Feature geometries not required", 4 ); mLoadGeometry = false; } // ensure that all attributes required for expression filter are being fetched if ( mRequest.flags() & QgsFeatureRequest::SubsetOfAttributes && request.filterType() == QgsFeatureRequest::FilterExpression ) { QgsAttributeList attrs = request.subsetOfAttributes(); //ensure that all fields required for filter expressions are prepared QSet<int> attributeIndexes = request.filterExpression()->referencedAttributeIndexes( mSource->mFields ); attributeIndexes += attrs.toSet(); mRequest.setSubsetOfAttributes( attributeIndexes.toList() ); } // also need attributes required by order by if ( mRequest.flags() & QgsFeatureRequest::SubsetOfAttributes && !mRequest.orderBy().isEmpty() ) { QgsAttributeList attrs = request.subsetOfAttributes(); Q_FOREACH ( const QString &attr, mRequest.orderBy().usedAttributes() ) { int attrIndex = mSource->mFields.lookupField( attr ); if ( !attrs.contains( attrIndex ) ) attrs << attrIndex; } mRequest.setSubsetOfAttributes( attrs ); }
QgsSpatiaLiteFeatureIterator::QgsSpatiaLiteFeatureIterator( QgsSpatiaLiteFeatureSource* source, bool ownSource, const QgsFeatureRequest& request ) : QgsAbstractFeatureIteratorFromSource<QgsSpatiaLiteFeatureSource>( source, ownSource, request ) , sqliteStatement( nullptr ) , mExpressionCompiled( false ) { mHandle = QgsSpatiaLiteConnPool::instance()->acquireConnection( mSource->mSqlitePath ); mFetchGeometry = !mSource->mGeometryColumn.isNull() && !( mRequest.flags() & QgsFeatureRequest::NoGeometry ); mHasPrimaryKey = !mSource->mPrimaryKey.isEmpty(); mRowNumber = 0; QStringList whereClauses; bool useFallbackWhereClause = false; QString fallbackWhereClause; QString whereClause; //beware - limitAtProvider needs to be set to false if the request cannot be completely handled //by the provider (eg utilising QGIS expression filters) bool limitAtProvider = ( mRequest.limit() >= 0 ); if ( !request.filterRect().isNull() && !mSource->mGeometryColumn.isNull() ) { // some kind of MBR spatial filtering is required whereClause = whereClauseRect(); if ( ! whereClause.isEmpty() ) { whereClauses.append( whereClause ); } } if ( !mSource->mSubsetString.isEmpty() ) { whereClause = "( " + mSource->mSubsetString + ')'; if ( ! whereClause.isEmpty() ) { whereClauses.append( whereClause ); } } if ( request.filterType() == QgsFeatureRequest::FilterFid ) { whereClause = whereClauseFid(); if ( ! whereClause.isEmpty() ) { whereClauses.append( whereClause ); } } else if ( request.filterType() == QgsFeatureRequest::FilterFids ) { whereClause = whereClauseFids(); if ( ! whereClause.isEmpty() ) { whereClauses.append( whereClause ); } } //IMPORTANT - this MUST be the last clause added! else if ( request.filterType() == QgsFeatureRequest::FilterExpression ) { // ensure that all attributes required for expression filter are being fetched if ( mRequest.flags() & QgsFeatureRequest::SubsetOfAttributes && request.filterType() == QgsFeatureRequest::FilterExpression ) { QgsAttributeList attrs = request.subsetOfAttributes(); Q_FOREACH ( const QString& field, request.filterExpression()->referencedColumns() ) { int attrIdx = mSource->mFields.fieldNameIndex( field ); if ( !attrs.contains( attrIdx ) ) attrs << attrIdx; } mRequest.setSubsetOfAttributes( attrs ); } if ( QSettings().value( "/qgis/compileExpressions", true ).toBool() ) { QgsSpatiaLiteExpressionCompiler compiler = QgsSpatiaLiteExpressionCompiler( source ); QgsSqlExpressionCompiler::Result result = compiler.compile( request.filterExpression() ); if ( result == QgsSqlExpressionCompiler::Complete || result == QgsSqlExpressionCompiler::Partial ) { whereClause = compiler.result(); if ( !whereClause.isEmpty() ) { useFallbackWhereClause = true; fallbackWhereClause = whereClauses.join( " AND " ); whereClauses.append( whereClause ); //if only partial success when compiling expression, we need to double-check results using QGIS' expressions mExpressionCompiled = ( result == QgsSqlExpressionCompiler::Complete ); } } if ( result != QgsSqlExpressionCompiler::Complete ) { //can't apply limit at provider side as we need to check all results using QGIS expressions limitAtProvider = false; } } else { limitAtProvider = false; } }