Package org.eclipse.persistence.queries

Class DeleteAllQuery

  • All Implemented Interfaces:
    Serializable, Cloneable
    public class DeleteAllQuery
extends ModifyAllQuery

    Purpose: Query used to delete a collection of objects. This is used by mappings to delete all of their target objects in a single database call. The SQL/SQLStatements must be provided.

    DeleteAll can also be used with an Expression (or JPQL) to dynamically delete a set of objects from the database, and invalidate them in the cache.

    Responsibilities:

    • Stores & retrieves the objects to delete.
    • Store the where clause used for the deletion.
    Since:
    TOPLink/Java 1.0
    Author:
    Yvon Lavoie
    See Also:
    Serialized Form

    • Field Detail

      • objects

        protected List<Object> objects
        List containing objects to be deleted, these should be removed from the identity map after deletion.

      • isInMemoryOnly

        protected boolean isInMemoryOnly
        Defines if objects should be remove from the persistence context only (no database). This is used if delete was already cascaded by the database.

    • Constructor Detail

      • DeleteAllQuery

        public DeleteAllQuery()
        PUBLIC:

      • DeleteAllQuery

        public DeleteAllQuery​(Class referenceClass)
        PUBLIC: Create a new delete all query for the class specified.

      • DeleteAllQuery

        public DeleteAllQuery​(Class referenceClass,
                      Expression selectionCriteria)
        PUBLIC: Create a new delete all query for the class and the selection criteria specified.

    • Method Detail

      • isInMemoryOnly

        public boolean isInMemoryOnly()
        INTERNAL: Return if objects should be remove from the persistence context only (no database). This is used if delete was already cascaded by the database.

      • setIsInMemoryOnly

        public void setIsInMemoryOnly​(boolean isInMemoryOnly)
        INTERNAL: Set if objects should be remove from the persistence context only (no database). This is used if delete was already cascaded by the database.

      • isDeleteAllQuery

        public boolean isDeleteAllQuery()
        PUBLIC: Return if this is a delete all query.
        Overrides:
        isDeleteAllQuery in class DatabaseQuery

      • executeInUnitOfWork

        public Object executeInUnitOfWork​(UnitOfWorkImpl unitOfWork,
                                  AbstractRecord translationRow)
                           throws DatabaseException
        INTERNAL: This method has to be broken. If commit manager is not active either an exception should be thrown (ObjectLevelModify case), or a transaction should be started early and execute on parent if remote (dataModify case). A modify query is NEVER executed on the parent, unless remote session.
        Overrides:
        executeInUnitOfWork in class ModifyAllQuery
        Parameters:
        unitOfWork - - the session in which the receiver will be executed.
        translationRow - - the arguments
        Returns:
        An object, the result of executing the query.
        Throws:
        DatabaseException - - an error has occurred on the database.

      • executeDatabaseQuery

        public Object executeDatabaseQuery()
                            throws DatabaseException
        INTERNAL: Perform the work to delete a collection of objects. This skips the optimistic lock check and should not called for objects using locking.
        Specified by:
        executeDatabaseQuery in class DatabaseQuery
        Returns:
        Integer the number of objects (rows) deleted.
        Throws:
        DatabaseException - - an error has occurred on the database.

      • getDefaultRedirector

        protected QueryRedirector getDefaultRedirector()
        INTERNAL: Returns the specific default redirector for this query type. There are numerous default query redirectors. See ClassDescriptor for their types.
        Overrides:
        getDefaultRedirector in class DatabaseQuery

      • getObjects

        public List<Object> getObjects()
        PUBLIC: Return the objects that are to be deleted

      • setObjects

        public void setObjects​(List<Object> objectCollection)
        PUBLIC (REQUIRED): Set the objects to be deleted. Also REQUIRED is a selection criteria or SQL string that performs the deletion of the objects. This does not generate the SQL call from the deleted objects.

        List objects used as an indicator of one of two possible ways the query may behave:

        objects != null - the "old" functionality used by OneToMany mapping objects deleted from the cache, either selection expression or custom sql should be provided for deletion from db;

        objects == null - the "new" functionality (on par with UpdateAllQuery) the cache is either left alone or in-memory query finds the cached objects to be deleted, and these objects are invalidated in cache.

        Note that empty objects is still objects != case. Signal that no cache altering is required. Used by AggregationCollectionMapping and OneToManyMapping in case they use indirection and the ValueHolder has not been instantiated.