/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.envers.query.criteria;
import java.util.ArrayList;
import java.util.List;
import org.hibernate.envers.configuration.spi.AuditConfiguration;
import org.hibernate.envers.internal.reader.AuditReaderImplementor;
import org.hibernate.envers.internal.tools.query.Parameters;
import org.hibernate.envers.internal.tools.query.QueryBuilder;
import org.hibernate.envers.query.criteria.internal.CriteriaTools;
import org.hibernate.envers.query.internal.property.PropertyNameGetter;
/**
* @author Adam Warski (adam at warski dot org)
* @author Lukasz Antoniak (lukasz dot antoniak at gmail dot com)
*/
public class AggregatedAuditExpression implements AuditCriterion, ExtendableCriterion {
private PropertyNameGetter propertyNameGetter;
private AggregatedMode mode;
private boolean correlate = false; // Correlate subquery with outer query by entity id.
private List<AuditCriterion> criterions;
public AggregatedAuditExpression(PropertyNameGetter propertyNameGetter, AggregatedMode mode) {
this.propertyNameGetter = propertyNameGetter;
this.mode = mode;
criterions = new ArrayList<AuditCriterion>();
}
public static enum AggregatedMode {
MAX,
MIN
}
public AggregatedAuditExpression add(AuditCriterion criterion) {
criterions.add( criterion );
return this;
}
public void addToQuery(
AuditConfiguration auditCfg, AuditReaderImplementor versionsReader, String entityName,
QueryBuilder qb, Parameters parameters) {
String propertyName = CriteriaTools.determinePropertyName(
auditCfg,
versionsReader,
entityName,
propertyNameGetter
);
CriteriaTools.checkPropertyNotARelation( auditCfg, entityName, propertyName );
// Make sure our conditions are ANDed together even if the parent Parameters have a different connective
Parameters subParams = parameters.addSubParameters( Parameters.AND );
// This will be the aggregated query, containing all the specified conditions
QueryBuilder subQb = qb.newSubQueryBuilder();
// Adding all specified conditions both to the main query, as well as to the
// aggregated one.
for ( AuditCriterion versionsCriteria : criterions ) {
versionsCriteria.addToQuery( auditCfg, versionsReader, entityName, qb, subParams );
versionsCriteria.addToQuery( auditCfg, versionsReader, entityName, subQb, subQb.getRootParameters() );
}
// Setting the desired projection of the aggregated query
switch ( mode ) {
case MIN:
subQb.addProjection( "min", propertyName, false );
break;
case MAX:
subQb.addProjection( "max", propertyName, false );
}
// Correlating subquery with the outer query by entity id. See JIRA HHH-7827.
if ( correlate ) {
final String originalIdPropertyName = auditCfg.getAuditEntCfg().getOriginalIdPropName();
auditCfg.getEntCfg().get( entityName ).getIdMapper().addIdsEqualToQuery(
subQb.getRootParameters(),
subQb.getRootAlias() + "." + originalIdPropertyName,
qb.getRootAlias() + "." + originalIdPropertyName
);
}
// Adding the constrain on the result of the aggregated criteria
subParams.addWhere( propertyName, "=", subQb );
}
/**
* Compute aggregated expression in the context of each entity instance separately. Useful for retrieving latest
* revisions of all entities of a particular type.<br/>
* Implementation note: Correlates subquery with the outer query by entity id.
*
* @return this (for method chaining).
*/
public AggregatedAuditExpression computeAggregationInInstanceContext() {
correlate = true;
return this;
}
}