IClassSchemaEdit3 Interface

Provides access to members that modify an object class's extension properties.

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Members

	Name	Description
	AddGlobalID	Adds a global ID column to a class and populates it with GUIDs.
	AlterAliasName	The alias name of the object class.
	AlterClassExtensionCLSID	Changes the class extension COM class associated with this database class.
	AlterClassExtensionProperties	Changes the class extension properties associated with this object class.
	AlterDefaultValue	The default value of the object class field.
	AlterDomain	The default domain of the object class field.
	AlterFieldAliasName	The alias name of the object class field.
	AlterFieldModelName	The model name of the object class field.
	AlterInstanceCLSID	Changes the instance COM class associated with this database class.
	AlterModelName	The model name of the object class.
	DeleteGlobalID	Deletes the global ID column.
	RegisterAsObjectClass	Registers this class with the database, assigning it a class id and creating an object id column.

Inherited Interfaces

Classes that implement IClassSchemaEdit3

Remarks

This interface can be used to add and delete fields of type GlobalID to a feature class or table.

A GlobalID value is an ArcGIS assigned ID value for a row that is set when the row is created. The GlobalID value is guaranteed to be unique at the time of creation across all geodatabases. An ObjectID value is also an ArcGIS assigned ID value for a row that is assigned when the row is created. The ObjectID value is guaranteed to be unique across all rows and across all versions of the table containing the row. It is not guaranteed to be unique across tables within a geodatabase or between geodatabases.

The GlobalID value can be used to correlate rows in different geodatabases. Processes such as replication, copy, extract, checkout, checkin, data changes import, and data changes export preserve GlobalIDs. If two rows from different geodatabases have the same GlobalID, they are interpreted to be different representations of the same 'real world' entity or relationship. Applications that use GlobalIDs to match rows between different geodatabases may add additional criteria such as matching table names to factor in possible schema changes. 

These fields are not editable and only one GlobalID column can exist per table. An alternative to adding a new GlobalID field is to register an existing GUID field as a GlobalID field, using the IClassSchemaEditEx interface.

GlobalID columns are required for replication and data exchange. Details on how to prepare data for replication can be found in the ArcGIS for Desktop web Help topic, Preparing data for replication. See the IReplicationAgent and IGeoDataServer interfaces, and the DataChangesExporter and DataChangesImporter classes (all can be found in the Geodatabase Distributed library) for more information about the APIs for these processes.

As with other schema editing operations, an exclusive schema lock should be acquired for a dataset prior to adding or deleted a GlobalID field.