* @param bookId the primary key of the s book
* @return the s book, or <code>null</code> if a s book with the primary key could not be found
* @throws SystemException if a system exception occurred
*/
public SBook fetchByPrimaryKey(long bookId) throws SystemException {
SBook sBook = (SBook)EntityCacheUtil.getResult(SBookModelImpl.ENTITY_CACHE_ENABLED,
SBookImpl.class, bookId);
if (sBook == _nullSBook) {
return null;
}