Name of the column the extension applies to, or null if it applies to
the whole table or GeoPackage.
Definition of the extension, typically a URI or a reference to the specification document (e.g., an OGC document identifier or Annex reference).
Registered extension name in the form <author>_<extension_name>
(e.g., 'gpkg_rtree_index').
Scope of the extension's effect:
'read-write' -- affects both reading and writing'write-update' -- affects only writing/updatingName of the table the extension applies to, or null if the extension
applies to the entire GeoPackage rather than a specific table.
Represents a row in the
gpkg_extensionstable.The extensions table registers the GeoPackage extensions in use, indicating which table and/or column an extension applies to, how it is defined, and whether it affects read or write operations. See the GeoPackage Extensions specification.