/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.criterion;

import java.util.Locale;

import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.TypedValue;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.Loadable;
import org.hibernate.sql.ConditionFragment;
import org.hibernate.type.StandardBasicTypes;

Used to define a restriction on a collection property based on its size.
Author:Gavin King, Steve Ebersole
/** * Used to define a restriction on a collection property based on its size. * * @author Gavin King * @author Steve Ebersole */
public class SizeExpression implements Criterion { private final String propertyName; private final int size; private final String op; protected SizeExpression(String propertyName, int size, String op) { this.propertyName = propertyName; this.size = size; this.op = op; } @Override public String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException { final String entityName =criteriaQuery.getEntityName( criteria, propertyName ); final String role = entityName + '.' + criteriaQuery.getPropertyName( propertyName ); final QueryableCollection cp = (QueryableCollection) criteriaQuery.getFactory().getCollectionPersister( role ); final String[] fk = cp.getKeyColumnNames(); final String[] pk = ( (Loadable) cp.getOwnerEntityPersister() ).getIdentifierColumnNames(); final ConditionFragment subQueryRestriction = new ConditionFragment() .setTableAlias( criteriaQuery.getSQLAlias( criteria, propertyName ) ) .setCondition( pk, fk ); return String.format( Locale.ROOT, "? %s (select count(*) from %s where %s)", op, cp.getTableName(), subQueryRestriction.toFragmentString() ); } @Override public TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException { return new TypedValue[] { new TypedValue( StandardBasicTypes.INTEGER, size ) }; } @Override public String toString() { return Integer.toString(size) + op + propertyName + ".size"; } }