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;
}
}
