public interface IlvObjectSDOKeyExtractor extends IlvPersistentObject
IlvObjectSDOKeyExtractor
extracts feature ID or
key of geometries stored in a database.The purpose of keys in databases is to allow you to identify a geometry by a unique ID. These keys are often composed of a unique column in the database, but are not limited to. A key can be composed from values stored in multiple columns.
The key extractor is used by the IlvObjectSDOFeatureIterator
to extract keys from ResultSets
, then this key is associated with
generated features as feature ID.
Typical use of extracted keys is to prevent tile loaders from loading multiple times a geometry belonging to multiple tiles.
IlvObjectSDOFeatureIterator
,
IlvObjectSDOLayer
Modifier and Type | Method and Description |
---|---|
Object |
extractKey(ResultSet set)
Extracts the key from the current row of the specified
ResultSet . |
boolean |
isPersistent()
Returns
true if this IlvObjectSDOKeyExtractor is
persistent. |
write
Object extractKey(ResultSet set) throws IlvSDOException
ResultSet
.set
- The ResultSet
where the key is to be extracted.Object
used as feature ID for the current row.IlvSDOException
boolean isPersistent()
true
if this IlvObjectSDOKeyExtractor
is
persistent.© Copyright 2024 Rogue Wave Software, Inc., a Perforce company.. All Rights Reserved.