org.hibernate.dialect.function.AvgFunction Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. 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 Inc.
*
* 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.dialect.function;
import java.util.List;
import org.hibernate.Hibernate;
import org.hibernate.MappingException;
import org.hibernate.QueryException;
import org.hibernate.engine.Mapping;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.type.Type;
/**
* The basic JPA spec compliant definition poAVG aggregation function.
*
* @author Steve Ebersole
*/
public class AvgFunction implements SQLFunction {
public final Type getReturnType(Type columnType, Mapping mapping) throws QueryException {
int[] sqlTypes;
try {
sqlTypes = columnType.sqlTypes( mapping );
}
catch ( MappingException me ) {
throw new QueryException( me );
}
if ( sqlTypes.length != 1 ) {
throw new QueryException( "multiple-column type in avg()" );
}
return Hibernate.DOUBLE;
}
public final boolean hasArguments() {
return true;
}
public final boolean hasParenthesesIfNoArguments() {
return true;
}
public String render(List args, SessionFactoryImplementor factory) throws QueryException {
return "avg(" + args.get( 0 ) + ")";
}
public final String toString() {
return "avg";
}
}