Package org.openhab.core.persistence

Interface QueryablePersistenceService

All Superinterfaces:
PersistenceService
All Known Subinterfaces:
ModifiablePersistenceService
@NonNullByDefault public interface QueryablePersistenceService extends PersistenceService
A queryable persistence service which can be used to store and retrieve data from openHAB. This is most likely some kind of database system.
Author:
Kai Kreuzer - Initial contribution, Chris Jackson - Added getItems method, Mark Herwege - Added methods to retrieve lastUpdate, lastChange and lastState from persistence, Mark Herwege - Implement aliases

  • Method Details

    • query

      Iterable<HistoricItem> query(FilterCriteria filter)
      Queries the PersistenceService for historic data with a given FilterCriteria. If the persistence service implementing this class supports using aliases for item names, the default implementation of query(FilterCriteria, String) should be overridden as well.
      Parameters:
      filter - the filter to apply to the query
      Returns:
      a time series of items

    • query

      default Iterable<HistoricItem> query(FilterCriteria filter, @Nullable String alias)
      Queries the PersistenceService for historic data with a given FilterCriteria. If the persistence service implementing this interface supports aliases and relies on item registry lookups, the default implementation should be overridden to query the database with the aliased name.
      Parameters:
      filter - the filter to apply to the query
      alias - for item name in database
      Returns:
      a time series of items

    • getItemInfo

      Set<PersistenceItemInfo> getItemInfo()
      Returns a set of PersistenceItemInfo about items that are stored in the persistence service. This allows the persistence service to return information about items that are no long available as an Item in openHAB. If it is not possible to retrieve the information an empty set should be returned. Note that implementations for method callers that this method may return an alias for an existing item if the database does not store the mapping between item name and alias or the reverse mapping is not implemented in the persistence service.
      Returns:
      a set of information about the persisted items

    • persistedItem

      default @Nullable PersistedItem persistedItem(String itemName, @Nullable String alias)
      Returns a PersistedItem representing the persisted state, last update and change timestamps and previous persisted state. This can be used to restore the full state of an item. The default implementation queries the service and iterates backward to find the last change and previous persisted state. Persistence services can override this default implementation with a more specific or efficient algorithm.
      Parameters:
      itemName - name of item
      alias - alias of item
      Returns:
      a PersistedItem or null if the item has not been persisted