org.jpox.store.rdbms.scostore
Class FKSetStore

java.lang.Object
  org.jpox.store.rdbms.scostore.ElementContainerStore
      org.jpox.store.rdbms.scostore.AbstractCollectionStore
          org.jpox.store.rdbms.scostore.FKSetStore

All Implemented Interfaces:

org.jpox.store.mapped.scostore.CollectionStoreQueryable, org.jpox.store.scostore.CollectionStore, org.jpox.store.scostore.SetStore, org.jpox.store.scostore.Store

public class FKSetStore
extends AbstractCollectionStore

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.

Version:

$Revision: 1.64 $

Nested Class Summary

Nested classes/interfaces inherited from class org.jpox.store.rdbms.scostore.ElementContainerStore

ElementContainerStore.ElementInfo

Field Summary

protected boolean	allowsNull Whether the container allows null elements/values.
protected org.jpox.store.mapped.DatastoreAdapter	dba Datastore adapter in use by this store.
protected static org.jpox.util.Localiser	LOCALISER Localiser for messages.
protected org.jpox.store.mapped.mapping.JavaTypeMapping	ownerMapping Mapping to the owner of the container.
protected org.jpox.metadata.AbstractMemberMetaData	ownerMemberMetaData MetaData for the field/property in the owner with this container.
protected java.lang.String	setName
protected RDBMSManager	storeMgr Manager for the store.

Fields inherited from class org.jpox.store.rdbms.scostore.AbstractCollectionStore

containsStmt

Fields inherited from class org.jpox.store.rdbms.scostore.ElementContainerStore

addStmt, clearStmt, clr, containerTable, elementInfo, elementIsPersistentInterface, elementMapping, elementsAreEmbedded, elementsAreSerialised, elementType, elmIdentifier, emd, iterateUsingDiscriminator, orderMapping, relationDiscriminatorMapping, relationDiscriminatorValue, removeStmt, usingDiscriminatorInSizeStmt

Constructor Summary

FKSetStore(org.jpox.metadata.AbstractMemberMetaData fmd, RDBMSManager storeMgr, org.jpox.ClassLoaderResolver clr)
Constructor for the relationship representation.

Method Summary

boolean	add(org.jpox.StateManager sm, java.lang.Object element, int size) Method to add an object to the relationship at the collection end.
boolean	addAll(org.jpox.StateManager sm, java.util.Collection elements, int size) Method to add a collection of object to the relationship at the collection end.
protected boolean	allowsBatching() Convenience method to return if the RDBMS supports batching and the user wants batching.
void	clear(org.jpox.StateManager ownerSM) Method to allow the Set relationship to be cleared out.
protected java.lang.String	getClearNullifyStmt() Generates the statement for clearing items by nulling the owner link out.
protected java.lang.String	getContainsStmt() Generate statement for retrieving the contents of the Collection.
protected int	getFieldNumberInElementForBidirectional(org.jpox.StateManager sm) This seems to return the field number in the element of the relation when it is a bidirectional relation.
protected org.jpox.store.mapped.expression.QueryExpression	getIteratorStatement(org.jpox.StateManager ownerSM) Accessor for a QueryStatement to retrieve the elements of the set.
org.jpox.store.mapped.mapping.JavaTypeMapping	getOwnerMapping() Accessor for the owner mapping.
protected java.lang.String	getSizeStmt() Generate statement for getting the size of the container.
protected org.jpox.StateManager	getStateManagerForEmbeddedPCObject(org.jpox.StateManager sm, java.lang.Object obj, JoinTable table) Method to return the StateManager for an embedded PC object (element, key, value).
org.jpox.store.StoreManager	getStoreManager() Accessor for the RDBMSManager.
protected int[]	internalAdd(org.jpox.StateManager ownerSM, org.jpox.ManagedConnection conn, boolean batched, java.lang.Object element, boolean processNow) Method to process an "add" statement.
protected int[]	internalRemove(org.jpox.StateManager ownerSM, org.jpox.ManagedConnection conn, boolean batched, java.lang.Object element, boolean executeNow) Method to process a "remove" statement.
protected boolean	isEmbeddedMapping(org.jpox.store.mapped.mapping.JavaTypeMapping mapping) Check if the mapping correspond to a non pc object or embedded field
java.util.Iterator	iterator(org.jpox.StateManager ownerSM) Accessor for an iterator for the set.
org.jpox.store.mapped.expression.ScalarExpression	joinElementsTo(org.jpox.store.mapped.expression.QueryExpression stmt, org.jpox.store.mapped.expression.QueryExpression parentStmt, org.jpox.store.mapped.mapping.JavaTypeMapping ownerMapping, org.jpox.store.mapped.expression.LogicSetExpression ownerTe, org.jpox.store.mapped.DatastoreIdentifier setTableAlias, java.lang.Class filteredElementType, org.jpox.store.mapped.expression.ScalarExpression elementExpr, org.jpox.store.mapped.DatastoreIdentifier elementTableAlias, boolean existsQuery) Utility for use in building a query, joining the element table and the owner table.
org.jpox.store.mapped.expression.QueryExpression	newQueryStatement(org.jpox.StateManager sm, java.lang.String candidateClass, org.jpox.store.mapped.DatastoreIdentifier candidateAlias) Utility method to return a new QueryStatement for retrieval of the elements of this Set.
protected int	populateOwnerInStatement(org.jpox.StateManager sm, org.jpox.ObjectManager om, java.sql.PreparedStatement ps, int jdbcPosition) Convenience method to populate the passed PreparedStatement with the value from the owner.
boolean	remove(org.jpox.StateManager sm, java.lang.Object element, int size, boolean allowDependentField) Method to remove the link to the collection object specified.
boolean	removeAll(org.jpox.StateManager sm, java.util.Collection elements, int size) Method to remove the links to a collection of elements specified.
protected void	setOwnerMemberMetaData(org.jpox.metadata.AbstractMemberMetaData mmd) Method to set the owner field/property MetaData and sets whether null elements/values are allowed.

Methods inherited from class org.jpox.store.rdbms.scostore.AbstractCollectionStore

contains, getExistsSubquery, getRemoveStmt, getSizeSubquery, getUpdateEmbeddedElementStmt, updateEmbeddedElement

Methods inherited from class org.jpox.store.rdbms.scostore.ElementContainerStore

getAddStmt, getClearStmt, getElementInformationForClass, getElementType, hasOrderMapping, newResultObjectFactory, populateElementDiscriminatorInStatement, populateElementInStatement, populateEmbeddedElementFieldsInStatement, populateOrderInStatement, populateRelationDiscriminatorInStatement, size, validateElementForReading, validateElementForWriting, validateElementType

Methods inherited from class java.lang.Object

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

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

contains, getElementType, hasOrderMapping, size, updateEmbeddedElement

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

getStoreManager

Methods inherited from interface org.jpox.store.mapped.scostore.CollectionStoreQueryable

newResultObjectFactory

Field Detail

setName

protected java.lang.String setName

LOCALISER

protected static final org.jpox.util.Localiser LOCALISER

Localiser for messages.

storeMgr

protected RDBMSManager storeMgr

Manager for the store.

dba

protected org.jpox.store.mapped.DatastoreAdapter dba

Datastore adapter in use by this store.

ownerMapping

protected org.jpox.store.mapped.mapping.JavaTypeMapping ownerMapping

Mapping to the owner of the container.

ownerMemberMetaData

protected org.jpox.metadata.AbstractMemberMetaData ownerMemberMetaData

MetaData for the field/property in the owner with this container.

allowsNull

protected boolean allowsNull

Whether the container allows null elements/values.

Constructor Detail

FKSetStore

public FKSetStore(org.jpox.metadata.AbstractMemberMetaData fmd,
                  RDBMSManager storeMgr,
                  org.jpox.ClassLoaderResolver clr)

Constructor for the relationship representation.

Parameters:

fmd - The MetaData for the field that this represents

storeMgr - The RDBMSManager managing the associated datastore.

clr - The ClassLoaderResolver

Method Detail

getSizeStmt

protected java.lang.String getSizeStmt()

Generate statement for getting the size of the container. The order part is only present when an order mapping is used. The discriminator part is only present when the element type has inheritance strategy of "superclass-table" and is Inverse.

 SELECT COUNT(*) FROM CONTAINERTABLE
 WHERE OWNERCOL=?
 [AND ORDERCOL IS NOT NULL]
 [AND (DISCRIMINATOR=? OR DISCRMINATOR=? OR DISCRIMINATOR=?)]
 

The discriminator part includes all subclasses of the element type

Overrides:

getSizeStmt in class ElementContainerStore

Returns:

The Statement returning the size of the container.

getContainsStmt

protected java.lang.String getContainsStmt()

Generate statement for retrieving the contents of the Collection. The discriminator part is only present when the element type has inheritance strategy of "superclass-table" and is Inverse.

 
 SELECT OWNERCOL FROM COLLECTIONTABLE 
 WHERE OWNERCOL=?
 AND ELEMENTCOL = ?
 [AND DISCRIMINATOR = ?]
 

Overrides:

getContainsStmt in class AbstractCollectionStore

Returns:

Statement for retrieving the contents of the Collection.

getClearNullifyStmt

protected java.lang.String getClearNullifyStmt()

Generates the statement for clearing items by nulling the owner link out. The statement will be

 UPDATE LISTTABLE SET OWNERCOL=NULL [,DISTINGUISHER=NULL]
 WHERE OWNERCOL=?
 

when there is only one element table, and will be

 UPDATE ? SET OWNERCOL=NULL [,DISTINGUISHER=NULL]
 WHERE OWNERCOL=?
 

when there is more than 1 element table.

Returns:

The Statement for clearing items for the owner.

getFieldNumberInElementForBidirectional

protected int getFieldNumberInElementForBidirectional(org.jpox.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

add

public boolean add(org.jpox.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 org.jpox.store.scostore.CollectionStore

Parameters:

sm - StateManager of the owner of the Set

element - Element to be added

Returns:

Success indicator

addAll

public boolean addAll(org.jpox.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 org.jpox.store.scostore.CollectionStore

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(org.jpox.StateManager sm,
                      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 org.jpox.store.scostore.CollectionStore

Parameters:

sm - 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(org.jpox.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 org.jpox.store.scostore.CollectionStore

Parameters:

sm - The StateManager of the Set

elements - The elements of the collection to be deleted.

Returns:

A success indicator.

clear

public void clear(org.jpox.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 org.jpox.store.scostore.CollectionStore

Overrides:

clear in class ElementContainerStore

Parameters:

ownerSM - StateManager of the Set

getIteratorStatement

protected org.jpox.store.mapped.expression.QueryExpression getIteratorStatement(org.jpox.StateManager ownerSM)

Accessor for a QueryStatement to retrieve the elements of the set.

Parameters:

ownerSM - the owner StateManager

Returns:

The QueryStatement to retrieve the elements

newQueryStatement

public org.jpox.store.mapped.expression.QueryExpression newQueryStatement(org.jpox.StateManager sm,
                                                                          java.lang.String candidateClass,
                                                                          org.jpox.store.mapped.DatastoreIdentifier candidateAlias)

Utility method to return a new QueryStatement for retrieval of the elements of this Set.

Parameters:

sm - StateManager for this object

candidateClass - Class for the element end of the link.

candidateAlias - Alias for the candidate

Returns:

The QueryStatement

joinElementsTo

public org.jpox.store.mapped.expression.ScalarExpression joinElementsTo(org.jpox.store.mapped.expression.QueryExpression stmt,
                                                                        org.jpox.store.mapped.expression.QueryExpression parentStmt,
                                                                        org.jpox.store.mapped.mapping.JavaTypeMapping ownerMapping,
                                                                        org.jpox.store.mapped.expression.LogicSetExpression ownerTe,
                                                                        org.jpox.store.mapped.DatastoreIdentifier setTableAlias,
                                                                        java.lang.Class filteredElementType,
                                                                        org.jpox.store.mapped.expression.ScalarExpression elementExpr,
                                                                        org.jpox.store.mapped.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

iterator

public java.util.Iterator iterator(org.jpox.StateManager ownerSM)

Accessor for an iterator for the set.

Specified by:

iterator in interface org.jpox.store.scostore.CollectionStore

Specified by:

iterator in class ElementContainerStore

Parameters:

ownerSM - State Manager for the set.

Returns:

Iterator for the set.

internalAdd

protected int[] internalAdd(org.jpox.StateManager ownerSM,
                            org.jpox.ManagedConnection conn,
                            boolean batched,
                            java.lang.Object element,
                            boolean processNow)
                     throws java.sql.SQLException

Method to process an "add" statement.

Parameters:

ownerSM - StateManager for the owner

conn - The connection

batched - Whether we are batching it

element - The element

Returns:

Number of datastore records changed (always 0 if batch since nothing yet changed)

Throws:

java.sql.SQLException - Thrown if an error occurs

internalRemove

protected int[] internalRemove(org.jpox.StateManager ownerSM,
                               org.jpox.ManagedConnection conn,
                               boolean batched,
                               java.lang.Object element,
                               boolean executeNow)
                        throws java.sql.SQLException

Method to process a "remove" statement.

Overrides:

internalRemove in class AbstractCollectionStore

Parameters:

ownerSM - StateManager for the owner

conn - The connection

batched - Whether we are batching it

element - The element

executeNow - Whether to execute the statement rather than allow batching til later

Returns:

Number of records changed (0 if batch since nothing yet changed)

Throws:

java.sql.SQLException - Thrown if an error occurs

setOwnerMemberMetaData

protected void setOwnerMemberMetaData(org.jpox.metadata.AbstractMemberMetaData mmd)

Method to set the owner field/property MetaData and sets whether null elements/values are allowed.

Parameters:

mmd - MetaData for the field/property owning this backing store.

getStoreManager

public org.jpox.store.StoreManager getStoreManager()

Accessor for the RDBMSManager.

Returns:

The RDBMSManager.

getOwnerMapping

public org.jpox.store.mapped.mapping.JavaTypeMapping getOwnerMapping()

Accessor for the owner mapping.

Returns:

Owner mapping.

isEmbeddedMapping

protected boolean isEmbeddedMapping(org.jpox.store.mapped.mapping.JavaTypeMapping mapping)

Check if the mapping correspond to a non pc object or embedded field

Parameters:

mapping - the mapping

Returns:

true if the field is embedded into one column

populateOwnerInStatement

protected int populateOwnerInStatement(org.jpox.StateManager sm,
                                       org.jpox.ObjectManager om,
                                       java.sql.PreparedStatement ps,
                                       int jdbcPosition)

Convenience method to populate the passed PreparedStatement with the value from the owner.

Parameters:

sm - State Manager

om - Object Manager

ps - The PreparedStatement

jdbcPosition - Position in JDBC statement to populate

Returns:

The next position in the JDBC statement

getStateManagerForEmbeddedPCObject

protected org.jpox.StateManager getStateManagerForEmbeddedPCObject(org.jpox.StateManager sm,
                                                                   java.lang.Object obj,
                                                                   JoinTable table)

Method to return the StateManager for an embedded PC object (element, key, value). It creates one if the element is not currently managed.

Parameters:

sm - State Manager of the owner

obj - The embedded PC object

table - Join table where the objects are stored

Returns:

The state manager

allowsBatching

protected boolean allowsBatching()

Convenience method to return if the RDBMS supports batching and the user wants batching.

Returns:

If batching of statements is permissible