// $Id: AbstractEmptinessExpression.java 6670 2005-05-03 22:19:00Z steveebersole $
package org.hibernate.criterion;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.QueryException;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.TypedValue;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.persister.entity.Loadable;
import org.hibernate.persister.entity.PropertyMapping;
import org.hibernate.sql.ConditionFragment;
import org.hibernate.type.CollectionType;
import org.hibernate.type.Type;
/**
* Implementation of AbstractEmptinessExpression.
*
* @author Steve Ebersole
*/
public abstract class AbstractEmptinessExpression implements Criterion {
private static final TypedValue[] NO_VALUES = new TypedValue[0];
protected final String propertyName;
protected AbstractEmptinessExpression(String propertyName) {
this.propertyName = propertyName;
}
protected abstract boolean excludeEmpty();
public final String toSqlString(Criteria criteria, CriteriaQuery criteriaQuery) throws HibernateException {
String entityName = criteriaQuery.getEntityName( criteria, propertyName );
String actualPropertyName = criteriaQuery.getPropertyName( propertyName );
String sqlAlias = criteriaQuery.getSQLAlias( criteria, propertyName );
SessionFactoryImplementor factory = criteriaQuery.getFactory();
QueryableCollection collectionPersister = getQueryableCollection( entityName, actualPropertyName, factory );
String[] collectionKeys = collectionPersister.getKeyColumnNames();
String[] ownerKeys = ( ( Loadable ) factory.getEntityPersister( entityName ) ).getIdentifierColumnNames();
String innerSelect = "(select 1 from " + collectionPersister.getTableName()
+ " where "
+ new ConditionFragment().setTableAlias( sqlAlias ).setCondition( ownerKeys, collectionKeys ).toFragmentString()
+ ")";
return excludeEmpty()
? "exists " + innerSelect
: "not exists " + innerSelect;
}
protected QueryableCollection getQueryableCollection(String entityName, String propertyName, SessionFactoryImplementor factory)
throws HibernateException {
PropertyMapping ownerMapping = ( PropertyMapping ) factory.getEntityPersister( entityName );
Type type = ownerMapping.toType( propertyName );
if ( !type.isCollectionType() ) {
throw new MappingException(
"Property path [" + entityName + "." + propertyName + "] does not reference a collection"
);
}
String role = ( ( CollectionType ) type ).getRole();
try {
return ( QueryableCollection ) factory.getCollectionPersister( role );
}
catch ( ClassCastException cce ) {
throw new QueryException( "collection role is not queryable: " + role );
}
catch ( Exception e ) {
throw new QueryException( "collection role not found: " + role );
}
}
public final TypedValue[] getTypedValues(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException {
return NO_VALUES;
}
public final String toString() {
return propertyName + ( excludeEmpty() ? " is not empty" : " is empty" );
}
}
|