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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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package org.apache.cayenne.merge;
import java.util.ArrayList;
import java.util.List;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.map.DbJoin;
import org.apache.cayenne.map.DbRelationship;
import org.apache.cayenne.map.ObjAttribute;
import org.apache.cayenne.map.ObjEntity;
/**
* A {@link MergerToken} to remove a {@link DbAttribute} from a {@link DbEntity}.
*
*/
public class DropColumnToModel extends AbstractToModelToken.EntityAndColumn {
public DropColumnToModel(DbEntity entity, DbAttribute column) {
super(entity, column);
}
public MergerToken createReverse(MergerFactory factory) {
return factory.createAddColumnToDb(getEntity(), getColumn());
}
public void execute(MergerContext mergerContext) {
// remove relationships mapped to column. duplicate List to prevent
// ConcurrentModificationException
List<DbRelationship> dbRelationships = new ArrayList<DbRelationship>(getEntity()
.getRelationships());
for (DbRelationship dbRelationship : dbRelationships) {
for (DbJoin join : dbRelationship.getJoins()) {
if (join.getSource() == getColumn() || join.getTarget() == getColumn()) {
remove(mergerContext, dbRelationship, true);
}
}
}
// remove ObjAttribute mapped to same column
for (ObjEntity objEntity : objEntitiesMappedToDbEntity(getEntity())) {
ObjAttribute objAttribute = objEntity.getAttributeForDbAttribute(getColumn());
if (objAttribute != null) {
objEntity.removeAttribute(objAttribute.getName());
mergerContext.getModelMergeDelegate().objAttributeRemoved(objAttribute);
}
}
// remove DbAttribute
getEntity().removeAttribute(getColumn().getName());
mergerContext.getModelMergeDelegate().dbAttributeRemoved(getColumn());
}
public String getTokenName() {
return "Drop Column";
}
}