Possibility of Adding or Removing Objects

Not all collections support possibility to add and remove objects. For some collections, an object will be added to the collection at its creation (e.g., the GeoDatabase object is added automatically to the GDBEngine::GeoDatabases collection when GDB is opened by the GDBEngine::OpenGDB method). The open mode of GDB, which is direct or indirect owner of collection, influences the possibility to add and remove an object as well (e.g., adding or removing the Table object to the GeoDatabase::Tables collection (from the collection) is impossible if GDB, the owner of collection, is opened on shared access). Objects are removed from some collections when they are closed by the Close method (e.g., the GeoDatabase object is removed from the GDBEngine::GeoDatabases collection when GDB is closed by the GeoDatabase::Close method). For some collections, the set of objects is formed by kernel of GIS and such collections do not support possibility to add or remove objects (e.g., the GeoDatabase::Sessions collection contains the Session objects which are descriptors of shared access sessions). The table below defines possibility to add and remove objects by the Append and Delete methods of collections.

Collection	Adding	Removing
DataLink::IndirectFieldsPairs	Possible if the DataLink::LinkCategory property returns gdbLinkIndirect.	Possible if the DataLink::LinkCategory property returns gdbLinkIndirect.
ExternalDatabase::Queries	Possible	Possible
ExternalDatabase::Recordsets	Impossible	Impossible
ExternalDatabase::Tables	Impossible	Possible
Feature::Themes	Possible if a theme is cataloged and a feature belongs to GDB map layer.	Possible
FeatureType::DataLinks	Possible when exclusive access to GDB. When shared access, possible if a link descriptor is based on a table or query that belongs to an uncataloged external database.	Possible when exclusive access to GDB. When shared access, possible if a link descriptor is based on a table or query that belongs to an uncataloged external database.
FeatureType::FilterGroups	Possible if a layer, the owner of feature type, belongs to the collection Theme::Layers.	Possible if a layer, the owner of feature type, belongs to the collection Theme::Layers.
Field::PrimaryKeys	Impossible	Impossible
ForeignKey::Fields	Impossible	Impossible
GDBEngine::ExternalDatabaseErrors	Impossible	Impossible
GDBEngine::GeoDatabases	Impossible	Impossible
GeoDatabase::ExternalDatabases	Possible	Possible. When shared access to GDB, possible for uncataloged external databases only. An external database must be closed.
GeoDatabase::Featuresets	Impossible	Impossible
GeoDatabase::Layouts	Possible	Possible
GeoDatabase::Maps	Possible when exclusive access to GDB	Possible when exclusive access to GDB
GeoDatabase::Queries	Possible	Possible
GeoDatabase::Recordsets	Impossible	Impossible
GeoDatabase::Sessions	Impossible	Impossible
GeoDatabase::Tables	Possible when exclusive access to GDB	Possible when exclusive access to GDB
GeoDatabase::TemporaryTables	Possible	Possible
GeoDatabase::Themes	Possible	Possible
GeoDatabase::Users	Possible when exclusive access to GDB	Possible when exclusive access to GDB
Layer::FeatureTypes	Possible when exclusive access to GDB	Possible when exclusive access to GDB
Layout::Elements	Possible	Possible
LayoutChartLegend::Keys	Impossible	Impossible
Legend::LegendItems	Impossible	Impossible
LegendItem:: LegendItems	Impossible	Impossible
Library::FillStyles	Possible	Possible
Library::Fonts	Possible	Possible
Library::HatchStyles	Possible	Possible
Library::LineStyles	Possible	Possible
Library::MapSymbols	Possible	Possible
Map::Layers	Possible when exclusive access to GDB	Possible when exclusive access to GDB
PrimaryKey::Fields	Impossible	Impossible
Query::Fields	Impossible	Possible for calculated fields only
Query::FieldSearchConditions	Possible	Possible
Query::FieldSortConditions	Possible	Possible
Query::SQLParameters	Possible	Possible
Recordset::Fields	Impossible	Impossible
Recordset::KeyFields	Possible for recordsets based on external tables or queries only.	Impossible
Recordset::SQLParameters	Impossible	Impossible
SharedLibrary::FillStyles	Possible	Possible
SharedLibrary::Fonts	Possible	Possible
SharedLibrary::HatchStyles	Possible	Possible
SharedLibrary::LineStyles	Possible	Possible
SharedLibrary::MapSymbols	Possible	Possible
SharedLibrary::Sessions	Impossible	Impossible
Table::Fields	Possible when exclusive access to GDB	Possible when exclusive access to GDB
Table::ForeignKeys	Impossible	Impossible
Table::PrimaryKeys	Impossible	Impossible
Table::SpecialFields	Impossible	Impossible
Table::TableIndexes	Impossible	Impossible
TableIndex::Fields	Impossible	Impossible
Theme::FeaturesetConditions	Possible	Possible
Theme::Layers	Possible	Possible
Theme::ScaleZones	Possible	Possible