org.datanucleus.store.rdbms.table
Class CollectionTable

java.lang.Object
  org.datanucleus.store.rdbms.table.AbstractTable
      org.datanucleus.store.rdbms.table.TableImpl
          org.datanucleus.store.rdbms.table.JoinTable
              org.datanucleus.store.rdbms.table.ElementContainerTable
                  org.datanucleus.store.rdbms.table.CollectionTable

All Implemented Interfaces:

org.datanucleus.store.mapped.DatastoreContainerObject, org.datanucleus.store.mapped.DatastoreElementContainer, Table

public class CollectionTable
extends ElementContainerTable
implements org.datanucleus.store.mapped.DatastoreElementContainer

Representation of a join table for a Collection. A Collection covers a wide range of possibilities in terms of whether it allows duplicates or not, whether it allows nulls or not, whether it supports ordering via indexes, whether it supports ordering via a SELECT criteria, etc. Consequently the join table can vary depending on the required capabilities.

JoinTable Mappings

The join table consists of the following mappings :-

• ownerMapping linking back to the owning class with the Collection.
• elementMapping either being an FK link to the element table or being an embedded/serialised element stored wholly in this table.
• orderMapping which may be null, or otherwise stores an index for the elements. This is either to provide uniqueness or ordering in a List (and part of the PK).

Field Summary

Fields inherited from class org.datanucleus.store.rdbms.table.ElementContainerTable

elementMapping, orderMapping, relationDiscriminatorMapping, relationDiscriminatorValue

Fields inherited from class org.datanucleus.store.rdbms.table.JoinTable

mmd, ownerMapping, ownerType

Fields inherited from class org.datanucleus.store.rdbms.table.AbstractTable

columns, columnsByName, dba, existsInDatastore, identifier, LOCALISER, state, storeMgr, TABLE_STATE_INITIALIZED, TABLE_STATE_INITIALIZED_MODIFIED, TABLE_STATE_NEW, TABLE_STATE_PK_INITIALIZED, TABLE_STATE_VALIDATED

Constructor Summary

CollectionTable(org.datanucleus.store.mapped.DatastoreIdentifier tableName, org.datanucleus.metadata.AbstractMemberMetaData mmd, RDBMSStoreManager storeMgr)
Constructor.

Method Summary

String	getElementType() Accessor for the element type stored in this Collection/Set/List.
void	initialize(org.datanucleus.ClassLoaderResolver clr) Method to initialise the table definition.
boolean	isEmbeddedElement() Accessor for whether the element is embedded into this table.
boolean	isEmbeddedElementPC() Accessor for whether the element is a PersistenceCapable(embedded).
boolean	isSerialisedElement() Accessor for whether the element is serialised into this table.
boolean	isSerialisedElementPC() Accessor for whether the element is a PersistenceCapable(serialised)
protected boolean	requiresPrimaryKey() Convenience method for whether a PK is required for the join table.

Methods inherited from class org.datanucleus.store.rdbms.table.ElementContainerTable

applyUserPrimaryKeySpecification, getElementMapping, getExpectedCandidateKeys, getExpectedForeignKeys, getExpectedIndices, getForeignKeyToElement, getForeignKeyToOwner, getMemberMapping, getOrderMapping, getRelationDiscriminatorMapping, getRelationDiscriminatorValue

Methods inherited from class org.datanucleus.store.rdbms.table.JoinTable

debugMapping, getIdMapping, getOwnerMapping, getOwnerMemberMetaData, getPrimaryKey

Methods inherited from class org.datanucleus.store.rdbms.table.TableImpl

createConstraints, dropConstraints, getSQLAddCandidateKeyStatements, getSQLAddFKStatements, getSQLCreateIndexStatements, getSQLCreateStatements, getSQLDropStatements, initializeColumnInfoForPrimaryKeyColumns, initializeColumnInfoFromDatastore, postInitialize, preInitialize, validate, validateColumns, validateConstraints, validatePrimaryKey

Methods inherited from class org.datanucleus.store.rdbms.table.AbstractTable

addColumnInternal, addDatastoreField, allowDDLOutput, assertIsInitialized, assertIsInitializedModified, assertIsPKInitialized, assertIsPKUninitialized, assertIsUninitialized, assertIsValidated, create, drop, equals, executeDdlStatement, executeDdlStatementList, exists, getCatalogName, getDatastoreField, getDatastoreFields, getDatastoreIdentifierFullyQualified, getDiscriminatorMapping, getDiscriminatorMetaData, getIdentifier, getMultitenancyMapping, getSchemaName, getStoreManager, getVersionMapping, getVersionMetaData, hasColumnName, hasDatastoreField, hashCode, isInitialized, isInitializedModified, isPKInitialized, isValidated, tableExistsInDatastore, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.datanucleus.store.mapped.DatastoreElementContainer

getElementMapping, getOwnerMapping

Methods inherited from interface org.datanucleus.store.mapped.DatastoreContainerObject

addDatastoreField, getDatastoreField, getDatastoreFields, getDiscriminatorMapping, getDiscriminatorMetaData, getIdentifier, getIdMapping, getMemberMapping, getMultitenancyMapping, getStoreManager, getVersionMapping, getVersionMetaData, hasDatastoreField

Constructor Detail

CollectionTable

public CollectionTable(org.datanucleus.store.mapped.DatastoreIdentifier tableName,
                       org.datanucleus.metadata.AbstractMemberMetaData mmd,
                       RDBMSStoreManager storeMgr)

Constructor.

Parameters:

tableName - Identifier name of the table

mmd - MetaData for the field of the owner

storeMgr - The Store Manager managing these tables.

Method Detail

initialize

public void initialize(org.datanucleus.ClassLoaderResolver clr)

Method to initialise the table definition.

Specified by:

initialize in interface Table

Overrides:

initialize in class ElementContainerTable

Parameters:

clr - The ClassLoaderResolver

getElementType

public String getElementType()

Accessor for the element type stored in this Collection/Set/List.

Specified by:

getElementType in class ElementContainerTable

Returns:

Name of element type.

isSerialisedElement

public boolean isSerialisedElement()

Accessor for whether the element is serialised into this table. This can be a serialised PersistenceCapable, or a serialised simple type

Returns:

Whether the element is serialised.

isEmbeddedElement

public boolean isEmbeddedElement()

Accessor for whether the element is embedded into this table. This can be an embedded PersistenceCapable, or an embedded simple type

Returns:

Whether the element is embedded.

isSerialisedElementPC

public boolean isSerialisedElementPC()

Accessor for whether the element is a PersistenceCapable(serialised)

Returns:

Whether the element is PC and is serialised

isEmbeddedElementPC

public boolean isEmbeddedElementPC()

Accessor for whether the element is a PersistenceCapable(embedded). Currently this only defines a PC element as embedded if the MetaData has an block. This may or may not be correct depending on how you interpret the JDO2 spec "embedded-element" flag.

Returns:

Whether the element is PC and is embedded

requiresPrimaryKey

protected boolean requiresPrimaryKey()

Convenience method for whether a PK is required for the join table. Extends JoinTable allowing for "ordered List" case which do not require a primary key (so we can have duplicates).

Overrides:

requiresPrimaryKey in class JoinTable

Returns:

Whether a PK is required