org.jpox.store.rdbms.scostore
Class JoinSetStore

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

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 JoinSetStore
extends AbstractCollectionStore

Representation of a Normal Set as part of a relationship. This class is used where you have a 1-N and the tables are joined via a link table. That is one table is the owner, and it has a link table to another table, with the link table having 2 columns - the ids of the 2 tables. This is in contrast to InverseSetStore which represents 1-N relationships without using a link table (using an id in the other table).

For sets of primitive types (eg Date,String etc), the NormalSetStore is used, but the 'link' table contains the id of the owner and the field(s) representing the primitive type.

Version:

$Revision: 1.53 $

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 java.lang.String	locateStmt Statement to check the existence of an owner-element relation.
protected boolean	m2n Whether this relation is one end of an M-N relation.
protected java.lang.String	maxOrderColumnIdStmt Statement to get the maximum order column id so we can set the next insert value.
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

JoinSetStore(org.jpox.metadata.AbstractMemberMetaData fmd, CollectionTable joinTable, org.jpox.ClassLoaderResolver clr)
Constructor for the relationship representation.

Method Summary

boolean	add(org.jpox.StateManager sm, java.lang.Object element, int size) Adds one element to the association owner vs elements.
boolean	addAll(org.jpox.StateManager sm, java.util.Collection elements, int size) Adds all elements from a collection to the association container.
protected boolean	allowsBatching() Convenience method to return if the RDBMS supports batching and the user wants batching.
protected org.jpox.store.mapped.expression.QueryExpression	getIteratorStatement(org.jpox.StateManager ownerSM) Accessor for the statement for the iterator.
org.jpox.store.mapped.mapping.JavaTypeMapping	getOwnerMapping() Accessor for the owner mapping.
protected java.lang.String	getRemoveAllStmt(org.jpox.StateManager ownerSm, java.util.Collection elements) Generate statement for removing a collection of items from the Set.
protected java.lang.String	getRemoveStmt() Generate statement for deleting items from the Set.
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 ownerTblExpr, 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.
boolean	locate(org.jpox.StateManager sm, java.lang.Object element) Method to check for the existence in the datastore of an owner-element relation.
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) Removes the association to one element
boolean	removeAll(org.jpox.StateManager sm, java.util.Collection elements, int size) Remove all elements from a collection from the association owner vs elements.
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, getContainsStmt, getExistsSubquery, getSizeSubquery, getUpdateEmbeddedElementStmt, updateEmbeddedElement

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

clear, getAddStmt, getClearStmt, getElementInformationForClass, getElementType, getSizeStmt, 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

clear, 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

locateStmt

protected java.lang.String locateStmt

Statement to check the existence of an owner-element relation.

maxOrderColumnIdStmt

protected java.lang.String maxOrderColumnIdStmt

Statement to get the maximum order column id so we can set the next insert value.

m2n

protected final boolean m2n

Whether this relation is one end of an M-N relation.

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

JoinSetStore

public JoinSetStore(org.jpox.metadata.AbstractMemberMetaData fmd,
                    CollectionTable joinTable,
                    org.jpox.ClassLoaderResolver clr)

Constructor for the relationship representation.

Parameters:

joinTable - The table for the link

clr - The ClassLoaderResolver

Method Detail

getRemoveStmt

protected java.lang.String getRemoveStmt()

Generate statement for deleting items from the Set. The EMBEDDEDFIELDX is only present when the elements are PC(embedded).

 DELETE FROM SETTABLE 
 WHERE OWNERCOL=?
 AND ELEMENTCOL = ?
 [AND EMBEDDEDFIELD1 = ? AND EMBEDDEDFIELD2 = ? AND EMBEDDEDFIELD3 = ?]
 [AND RELATION_DISCRIM = ?]
 

Overrides:

getRemoveStmt in class AbstractCollectionStore

Returns:

Statement for deleting items from the Set.

getRemoveAllStmt

protected java.lang.String getRemoveAllStmt(org.jpox.StateManager ownerSm,
                                            java.util.Collection elements)

Generate statement for removing a collection of items from the Set.

 DELETE FROM SETTABLE 
 WHERE (OWNERCOL=? AND ELEMENTCOL=?) OR
      (OWNERCOL=? AND ELEMENTCOL=?) OR
      (OWNERCOL=? AND ELEMENTCOL=?)
 

Parameters:

ownerSm - The owner StateManager

elements - Collection of elements to remove

Returns:

Statement for deleting items from the Set.

removeAll

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

Remove all elements from a collection from the association owner vs elements.

Specified by:

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

Parameters:

sm - State Manager for the container

elements - Collection of elements to remove

Returns:

Whether the database was updated

locate

public boolean locate(org.jpox.StateManager sm,
                      java.lang.Object element)

Method to check for the existence in the datastore of an owner-element relation.

Parameters:

sm - State Manager for the owner

element - The element

Returns:

Whether the relation exists in the datastore

add

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

Adds one element to the association owner vs elements.

Specified by:

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

Parameters:

sm - State Manager for the container.

element - Element to add

Returns:

Whether it was successful

addAll

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

Adds all elements from a collection to the association container.

Specified by:

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

Parameters:

sm - State Manager for the container.

elements - Collection of elements to add

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

Returns:

Whether it was successful

getIteratorStatement

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

Accessor for the statement for the iterator.

Parameters:

ownerSM - the owner StateManager

Returns:

The iterator Query Statement.

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 ownerTblExpr,
                                                                        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 no parent, "parentStmt" must be equal to "stmt"

ownerMapping - the mapping for the owner

ownerTblExpr - 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 element table expression

setTableAlias - The alias for the "Set" table

existsQuery - Whether this is joining for an EXISTS query

Returns:

Expression for the join

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

remove

public boolean remove(org.jpox.StateManager sm,
                      java.lang.Object element,
                      int size,
                      boolean allowDependentField)

Removes the association to one element

Specified by:

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

Parameters:

sm - State Manager for the container

element - Element to remove

size - Current size

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

Returns:

Whether it was successful

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