FeatureCursorOGR::FeatureCursorOGR(OGRDataSourceH dsHandle,
OGRLayerH layerHandle,
const FeatureProfile* profile,
const Symbology::Query& query,
const FeatureFilterList& filters ) :
_dsHandle( dsHandle ),
_layerHandle( layerHandle ),
_resultSetHandle( 0L ),
_profile( profile ),
_query( query ),
_filters( filters ),
_chunkSize( 500 ),
_nextHandleToQueue( 0L ),
_spatialFilter( 0L )
{
//_resultSetHandle = _layerHandle;
{
OGR_SCOPED_LOCK;
std::string expr;
std::string from = OGR_FD_GetName( OGR_L_GetLayerDefn( _layerHandle ));
from = std::string("'") + from + std::string("'");
if ( query.expression().isSet() )
{
// build the SQL: allow the Query to include either a full SQL statement or
// just the WHERE clause.
expr = query.expression().value();
// if the expression is just a where clause, expand it into a complete SQL expression.
std::string temp = expr;
std::transform( temp.begin(), temp.end(), temp.begin(), ::tolower );
bool complete = temp.find( "select" ) == 0;
if ( temp.find( "select" ) != 0 )
{
std::stringstream buf;
buf << "SELECT * FROM " << from << " WHERE " << expr;
std::string bufStr;
bufStr = buf.str();
expr = bufStr;
}
}
else
{
std::stringstream buf;
buf << "SELECT * FROM " << from;
expr = buf.str();
}
// if there's a spatial extent in the query, build the spatial filter:
if ( query.bounds().isSet() )
{
OGRGeometryH ring = OGR_G_CreateGeometry( wkbLinearRing );
OGR_G_AddPoint(ring, query.bounds()->xMin(), query.bounds()->yMin(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMin(), query.bounds()->yMax(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMax(), query.bounds()->yMax(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMax(), query.bounds()->yMin(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMin(), query.bounds()->yMin(), 0 );
_spatialFilter = OGR_G_CreateGeometry( wkbPolygon );
OGR_G_AddGeometryDirectly( _spatialFilter, ring );
// note: "Directly" above means _spatialFilter takes ownership if ring handle
}
_resultSetHandle = OGR_DS_ExecuteSQL( _dsHandle, expr.c_str(), _spatialFilter, 0L );
if ( _resultSetHandle )
{
OGR_L_ResetReading( _resultSetHandle );
}
}
readChunk();
}
FeatureCursorOGR::FeatureCursorOGR(OGRDataSourceH dsHandle,
OGRLayerH layerHandle,
const FeatureSource* source,
const FeatureProfile* profile,
const Symbology::Query& query,
const FeatureFilterList& filters ) :
_source ( source ),
_dsHandle ( dsHandle ),
_layerHandle ( layerHandle ),
_resultSetHandle ( 0L ),
_spatialFilter ( 0L ),
_query ( query ),
_chunkSize ( 500 ),
_nextHandleToQueue( 0L ),
_profile ( profile ),
_filters ( filters )
{
{
OGR_SCOPED_LOCK;
std::string expr;
std::string from = OGR_FD_GetName( OGR_L_GetLayerDefn( _layerHandle ));
std::string driverName = OGR_Dr_GetName( OGR_DS_GetDriver( dsHandle ) );
// Quote the layer name if it is a shapefile, so we can handle any weird filenames like those with spaces or hyphens.
// Or quote any layers containing spaces for PostgreSQL
if (driverName == "ESRI Shapefile" || from.find(" ") != std::string::npos)
{
std::string delim = "'"; //Use single quotes by default
if (driverName.compare("PostgreSQL") == 0)
{
//PostgreSQL uses double quotes as identifier delimeters
delim = "\"";
}
from = delim + from + delim;
}
if ( query.expression().isSet() )
{
// build the SQL: allow the Query to include either a full SQL statement or
// just the WHERE clause.
expr = query.expression().value();
// if the expression is just a where clause, expand it into a complete SQL expression.
std::string temp = expr;
std::transform( temp.begin(), temp.end(), temp.begin(), ::tolower );
//bool complete = temp.find( "select" ) == 0;
if ( temp.find( "select" ) != 0 )
{
std::stringstream buf;
buf << "SELECT * FROM " << from << " WHERE " << expr;
std::string bufStr;
bufStr = buf.str();
expr = bufStr;
}
}
else
{
std::stringstream buf;
buf << "SELECT * FROM " << from;
expr = buf.str();
}
//Include the order by clause if it's set
if (query.orderby().isSet())
{
std::string orderby = query.orderby().value();
std::string temp = orderby;
std::transform( temp.begin(), temp.end(), temp.begin(), ::tolower );
if ( temp.find( "order by" ) != 0 )
{
std::stringstream buf;
buf << "ORDER BY " << orderby;
std::string bufStr;
bufStr = buf.str();
orderby = buf.str();
}
expr += (" " + orderby );
}
// if there's a spatial extent in the query, build the spatial filter:
if ( query.bounds().isSet() )
{
OGRGeometryH ring = OGR_G_CreateGeometry( wkbLinearRing );
OGR_G_AddPoint(ring, query.bounds()->xMin(), query.bounds()->yMin(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMin(), query.bounds()->yMax(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMax(), query.bounds()->yMax(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMax(), query.bounds()->yMin(), 0 );
OGR_G_AddPoint(ring, query.bounds()->xMin(), query.bounds()->yMin(), 0 );
_spatialFilter = OGR_G_CreateGeometry( wkbPolygon );
OGR_G_AddGeometryDirectly( _spatialFilter, ring );
// note: "Directly" above means _spatialFilter takes ownership if ring handle
}
OE_DEBUG << LC << "SQL: " << expr << std::endl;
_resultSetHandle = OGR_DS_ExecuteSQL( _dsHandle, expr.c_str(), _spatialFilter, 0L );
if ( _resultSetHandle )
{
OGR_L_ResetReading( _resultSetHandle );
}
}
readChunk();
}
