org.exolab.castor.persist.spi
public interface PersistenceQuery
The caller takes full responsibility to assure integrity of transactions and object caching and only relies on the engine to assist in assuring that through the mechanisms available to it.
A query may be created once and used multiple times by calling the PersistenceQuery method. Query parameters are set each time prior to executing the query.
See Persistence for information about locks, loading objects, identities and stamps.
Version: $Revision: 6230 $ $Date: 2006-04-11 15:26:07 -0600 (Tue, 11 Apr 2006) $
See Also: Persistence
Method Summary | |
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boolean | absolute(int row)
Moves the result of the query to the absolute position in the
resultset.
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void | close()
Close the query and release all resources held by the query. |
void | execute(Object conn, AccessMode accessMode, boolean scrollable)
Execute the query with the give connection and lock type.
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Object | fetch(ProposedEntity proposedObject)
Loades the object. |
Class | getResultType()
Returns the type of object returned by this query.
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Identity | nextIdentity(Identity identity)
Returns the identity of the next object to be returned.
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void | setParameter(int index, Object value)
Sets the value of a paramter. |
int | size()
Finds the size of the resulting resultset from the query. |
Parameters: row The row to move to
Throws: PersistenceException A persistence error occured
Parameters: conn An open connection accessMode The access mode (null equals shared) scrollable The db cursor mode.
Throws: PersistenceException An invalid query or an error reported by the persistence engine.
If the object is locked by another transaction this method will block until the lock is released, or a timeout occured. If a timeout occurs or the object has been deleted by the other transaction, this method will report an ObjectNotFoundException. The query may proceed to the next identity.
This method is equivalent to Persistence with a known cache engine and access mode and acts on the query results rather than issuing a new query to load the object.
Parameters: proposedObject The fields to load into
Returns: The object's stamp, or null
Throws: PersistenceException The object was not found in persistent storage or any other persistence error occured.
See Also: Persistence
Returns: The type of object returned by this query
Parameters: identity The identity of the previous object, null if this method is called for the first time
Returns: The identity of the next object, null if the result set has been exhausted
Throws: PersistenceException An error reported by the persistence engine
Parameters: index The parameter index value The parameter value