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Plugin for DataNucleus providing persistence to RDBMS datastores.
There is a newer version: 6.0.7
/**********************************************************************
Copyright (c) 2005 Andy Jefferson and others. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. 


Contributors:
    ...
**********************************************************************/
package org.datanucleus.store.rdbms.table;

import org.datanucleus.ClassLoaderResolver;
import org.datanucleus.metadata.AbstractClassMetaData;
import org.datanucleus.metadata.AbstractMemberMetaData;
import org.datanucleus.metadata.ColumnMetaData;
import org.datanucleus.metadata.ElementMetaData;
import org.datanucleus.metadata.FieldRole;
import org.datanucleus.metadata.PrimaryKeyMetaData;
import org.datanucleus.store.rdbms.RDBMSStoreManager;
import org.datanucleus.store.rdbms.identifier.DatastoreIdentifier;
import org.datanucleus.util.ClassUtils;
import org.datanucleus.util.Localiser;
import org.datanucleus.util.NucleusLogger;

/**
 * Representation of a join table for an array. An array requires ordering of elements so that they can be stored
 * and retrieved in the same order.
 * 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 wholely in this table.
 * orderMapping providing the ordering of the elements.
 * 
 * The primary-key is formed from the ownerMapping and the orderMapping (unless overridden by the user).
 */
public class ArrayTable extends ElementContainerTable implements DatastoreElementContainer
{
    /**
     * Constructor.
     * @param ownerTable Table of the owner of this member
     * @param tableName Identifier name of the table
     * @param mmd MetaData for the member of the owner
     * @param storeMgr The Store Manager managing these tables.
     */
    public ArrayTable(Table ownerTable, DatastoreIdentifier tableName, AbstractMemberMetaData mmd, RDBMSStoreManager storeMgr)
    {
        super(ownerTable, tableName, mmd, storeMgr);
    }

    /**
     * Method to initialise the table definition.
     * @param clr The ClassLoaderResolver
     */
    public void initialize(ClassLoaderResolver clr)
    {
        super.initialize(clr);

        // Add field(s) for element
        boolean elementPC = (mmd.hasArray() && mmd.getArray().elementIsPersistent());
        if (isSerialisedElementPC() || isEmbeddedElementPC() || (isEmbeddedElement() && !elementPC) ||
            ClassUtils.isReferenceType(mmd.getType().getComponentType()))
        {
            // Element = PC(embedded), PC(serialised), Non-PC(embedded), Reference
            elementMapping = storeMgr.getMappingManager().getMapping(this, mmd, clr, FieldRole.ROLE_ARRAY_ELEMENT);
            if (Boolean.TRUE.equals(mmd.getContainer().allowNulls()))
            {
                // Make all element col(s) nullable so we can store null elements
                for (int i=0;i 0)
            {
                // Column mappings defined at this side (1-N, M-N)
                elemColmd = elemmd.getColumnMetaData();
            }
            elementMapping = ColumnCreator.createColumnsForJoinTables(mmd.getType().getComponentType(), mmd,
                elemColmd, storeMgr, this, false, true, FieldRole.ROLE_ARRAY_ELEMENT, clr, null);
            if (NucleusLogger.DATASTORE.isDebugEnabled())
            {
                logMapping(mmd.getFullFieldName()+".[ELEMENT]", elementMapping);
            }
        }

        boolean pkRequired = requiresPrimaryKey();
        PrimaryKeyMetaData pkmd = (mmd.getJoinMetaData() != null ? mmd.getJoinMetaData().getPrimaryKeyMetaData() : null);
        boolean pkColsSpecified = (pkmd != null ? pkmd.getColumnMetaData() != null : false);

        // Add order mapping
        ColumnMetaData colmd = null;
        if (mmd.getOrderMetaData() != null && mmd.getOrderMetaData().getColumnMetaData() != null &&
            mmd.getOrderMetaData().getColumnMetaData().length > 0)
        {
            // Specified "order" column info
            colmd = mmd.getOrderMetaData().getColumnMetaData()[0];
        }
        else
        {
            // No column name so use default
            DatastoreIdentifier id = storeMgr.getIdentifierFactory().newIndexFieldIdentifier(mmd);
            colmd = new ColumnMetaData();
            colmd.setName(id.getName());
        }

        orderMapping = storeMgr.getMappingManager().getMapping(int.class); // JDO2 spec [18.5] order column is assumed to be "int"
        ColumnCreator.createIndexColumn(orderMapping, storeMgr, clr, this, colmd, pkRequired && !pkColsSpecified);
        if (NucleusLogger.DATASTORE.isDebugEnabled())
        {
            logMapping(mmd.getFullFieldName()+".[ORDER]", orderMapping);
        }

        // Define primary key of the join table (if any)
        if (pkRequired)
        {
            if (pkColsSpecified)
            {
                // Apply the users PK specification
                applyUserPrimaryKeySpecification(pkmd);
            }
            else
            {
                // Define PK
                for (int i=0;i