org.datanucleus.store.mapped.scostore
Class FKSetStore

java.lang.Object
  org.datanucleus.store.mapped.scostore.BaseContainerStore
      org.datanucleus.store.mapped.scostore.ElementContainerStore
          org.datanucleus.store.mapped.scostore.AbstractCollectionStore
              org.datanucleus.store.mapped.scostore.AbstractSetStore
                  org.datanucleus.store.mapped.scostore.FKSetStore

All Implemented Interfaces:

CollectionStoreQueryable, CollectionStore, SetStore, Store

public abstract class FKSetStore
extends AbstractSetStore

Representation of an Inverse Set as part of a relationship. This class is used where you have a 1-N and the tables are not joined via a link table. That is there is an owner table, and a collection table, and the collection table has a column being the id of the owner table. This is in contrast to NormalSetStore which represents 1-N relationships using a link table. There are 2 possible uses here

• bidirectional - where the owner has a Collection of elements, and the element has an owner. In this case the element class will have an owner field which can be updated directly
• unidirectional - where the owner has a Collection of elements, but the element knows nothing about the owner. In this case the element class has no owner field. In this case the column in the element table has to be updated directly.

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.store.mapped.scostore.ElementContainerStore

ElementContainerStore.ElementInfo

Field Summary

Fields inherited from class org.datanucleus.store.mapped.scostore.ElementContainerStore

clr, containerTable, elementInfo, elementIsPersistentInterface, elementMapping, elementsAreEmbedded, elementsAreSerialised, elementType, emd, iterateUsingDiscriminator, orderMapping, relationDiscriminatorMapping, relationDiscriminatorValue, specialization

Fields inherited from class org.datanucleus.store.mapped.scostore.BaseContainerStore

allowsNull, dba, LOCALISER, ownerMapping, ownerMemberMetaData, relationType, storeMgr

Constructor Summary

FKSetStore(AbstractMemberMetaData fmd, MappedStoreManager storeMgr, ClassLoaderResolver clr, AbstractSetStoreSpecialization specialization)
Constructor for the relationship representation.

Method Summary

boolean	add(StateManager sm, java.lang.Object element, int size) Method to add an object to the relationship at the collection end.
boolean	addAll(StateManager sm, java.util.Collection elements, int size) Method to add a collection of object to the relationship at the collection end.
protected boolean	checkRemovalOfElementShouldDelete(StateManager ownerSM) Convenience method to return if the removal of an element should delete the element.
void	clear(StateManager ownerSM) Method to allow the Set relationship to be cleared out.
protected abstract void	clearInternal(StateManager ownerSM, ObjectManager om)
protected int	getFieldNumberInElementForBidirectional(StateManager sm) This seems to return the field number in the element of the relation when it is a bidirectional relation.
ScalarExpression	joinElementsTo(QueryExpression stmt, QueryExpression parentStmt, JavaTypeMapping ownerMapping, LogicSetExpression ownerTe, DatastoreIdentifier setTableAlias, java.lang.Class filteredElementType, ScalarExpression elementExpr, DatastoreIdentifier elementTableAlias, boolean existsQuery) Utility for use in building a query, joining the element table and the owner table.
protected void	manageRemovalOfElement(StateManager ownerSM, java.lang.Object element) Convenience method to manage the removal of an element from the collection, performing any necessary "managed relationship" updates when the field is bidirectional.
boolean	remove(StateManager ownerSM, java.lang.Object element, int size, boolean allowDependentField) Method to remove the link to the collection object specified.
boolean	removeAll(StateManager sm, java.util.Collection elements, int size) Method to remove the links to a collection of elements specified.
void	update(StateManager sm, java.util.Collection coll) Method to update the collection to be the supplied collection of elements.
protected abstract boolean	updateElementFkInternal(StateManager sm, java.lang.Object element, java.lang.Object owner)

Methods inherited from class org.datanucleus.store.mapped.scostore.AbstractSetStore

iterator

Methods inherited from class org.datanucleus.store.mapped.scostore.AbstractCollectionStore

contains, getExistsSubquery, getSizeSubquery, updateEmbeddedElement

Methods inherited from class org.datanucleus.store.mapped.scostore.ElementContainerStore

getContainerTable, getElementInfo, getElementInformationForClass, getElementMapping, getElementType, getEmd, getOrderMapping, getRelationDiscriminatorMapping, getRelationDiscriminatorValue, hasOrderMapping, isElementsAreEmbedded, isElementsAreSerialised, size, validateElementForReading, validateElementForWriting, validateElementType

Methods inherited from class org.datanucleus.store.mapped.scostore.BaseContainerStore

allowsBatching, getDatastoreAdapter, getOwnerMapping, getOwnerMemberMetaData, getRelationType, getStateManagerForEmbeddedPCObject, getStoreManager, isEmbeddedMapping, setOwner

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.datanucleus.store.scostore.CollectionStore

contains, getElementType, hasOrderMapping, size, updateEmbeddedElement

Methods inherited from interface org.datanucleus.store.scostore.Store

getStoreManager

Constructor Detail

FKSetStore

public FKSetStore(AbstractMemberMetaData fmd,
                  MappedStoreManager storeMgr,
                  ClassLoaderResolver clr,
                  AbstractSetStoreSpecialization specialization)

Constructor for the relationship representation.

Parameters:

fmd - The MetaData for the field that this represents

storeMgr - The MappedStoreManager managing the associated datastore.

clr - The ClassLoaderResolver

specialization - The datastore-specific specialization

Method Detail

getFieldNumberInElementForBidirectional

protected int getFieldNumberInElementForBidirectional(StateManager sm)

This seems to return the field number in the element of the relation when it is a bidirectional relation.

Parameters:

sm - StateManager of the owner

Returns:

The field number in the element for this relation

update

public void update(StateManager sm,
                   java.util.Collection coll)

Method to update the collection to be the supplied collection of elements.

Specified by:

update in interface CollectionStore

Overrides:

update in class AbstractCollectionStore

Parameters:

sm - StateManager of the object

coll - The collection to use

add

public boolean add(StateManager sm,
                   java.lang.Object element,
                   int size)

Method to add an object to the relationship at the collection end.

Specified by:

add in interface CollectionStore

Overrides:

add in class AbstractSetStore

Parameters:

sm - StateManager of the owner of the Set

element - Element to be added

size - Current size of the collection if known. -1 if not known

Returns:

Success indicator

addAll

public boolean addAll(StateManager sm,
                      java.util.Collection elements,
                      int size)

Method to add a collection of object to the relationship at the collection end.

Specified by:

addAll in interface CollectionStore

Overrides:

addAll in class AbstractSetStore

Parameters:

sm - StateManager of the Set

elements - Elements to be added

size - Current size of set (if known). Not used by sets

Returns:

Success indicator

remove

public boolean remove(StateManager ownerSM,
                      java.lang.Object element,
                      int size,
                      boolean allowDependentField)

Method to remove the link to the collection object specified. Depending on the column characteristics in the collection table, the id of the owner field may be NULLed, or the record may be deleted completely (as per cascade-delete in EJB).

Specified by:

remove in interface CollectionStore

Overrides:

remove in class AbstractSetStore

Parameters:

ownerSM - The StateManager of the Set

element - The element of the collection to be deleted.

allowDependentField - Whether to allow any cascade deletes caused by this removal

size - Current size

Returns:

A success indicator.

removeAll

public boolean removeAll(StateManager sm,
                         java.util.Collection elements,
                         int size)

Method to remove the links to a collection of elements specified. Depending on the column characteristics in the collection table, the id of the owner fields may be NULLed, or the records may be deleted completely.

Specified by:

removeAll in interface CollectionStore

Overrides:

removeAll in class AbstractSetStore

Parameters:

sm - The StateManager of the Set

elements - The elements of the collection to be deleted.

size - Current size of collection if known. -1 if not known

Returns:

A success indicator.

checkRemovalOfElementShouldDelete

protected boolean checkRemovalOfElementShouldDelete(StateManager ownerSM)

Convenience method to return if the removal of an element should delete the element.

Parameters:

ownerSM - StateManager for the owner

Returns:

Whether we should delete the element on removing from the collection

manageRemovalOfElement

protected void manageRemovalOfElement(StateManager ownerSM,
                                      java.lang.Object element)

Convenience method to manage the removal of an element from the collection, performing any necessary "managed relationship" updates when the field is bidirectional.

Parameters:

ownerSM - StateManager for the collection owner

element - The element

clear

public void clear(StateManager ownerSM)

Method to allow the Set relationship to be cleared out. This is called by the List.clear() method, or when the container object is being deleted and the elements are to be removed (maybe for dependent field), or also when updating a Collection and removing all existing prior to adding all new.

Specified by:

clear in interface CollectionStore

Overrides:

clear in class ElementContainerStore

Parameters:

ownerSM - StateManager of the Set

joinElementsTo

public ScalarExpression joinElementsTo(QueryExpression stmt,
                                       QueryExpression parentStmt,
                                       JavaTypeMapping ownerMapping,
                                       LogicSetExpression ownerTe,
                                       DatastoreIdentifier setTableAlias,
                                       java.lang.Class filteredElementType,
                                       ScalarExpression elementExpr,
                                       DatastoreIdentifier elementTableAlias,
                                       boolean existsQuery)

Utility for use in building a query, joining the element table and the owner table.

Parameters:

stmt - The Query Statement

parentStmt - the parent Query Statement. If there is no parent, parentStmt must be equals to stmt

ownerMapping - the mapping for the owner.

ownerTe - Table Expression for the owner

filteredElementType - The Class Type for the filtered element

elementExpr - The Expression for the element

elementTableAlias - The SQL alias to assign to the expression or to the element table.

setTableAlias - The alias for the "Set" table

existsQuery - Whether this is joining for an EXISTS query

Returns:

Expression for the id of the elements table

clearInternal

protected abstract void clearInternal(StateManager ownerSM,
                                      ObjectManager om)

updateElementFkInternal

protected abstract boolean updateElementFkInternal(StateManager sm,
                                                   java.lang.Object element,
                                                   java.lang.Object owner)