/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, 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.hql.internal.ast.tree;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.internal.util.StringHelper;
import antlr.SemanticException;
/**
* Represents a reference to a result_variable as defined in the JPA 2 spec.
* For example:
* <code>
* select v as value from tab1 order by value
* </code>
* <p/>
* "value" used in the order by clause is a reference to the
* result_variable, "value", defined in the select clause.
*
* @author Gail Badner
*/
public class ResultVariableRefNode extends HqlSqlWalkerNode {
private SelectExpression selectExpression;
/**
* Set the select expression that defines the result variable.
*
* @param selectExpression the select expression;
* selectExpression.getAlias() must be non-null
* @throws SemanticException if selectExpression or
* selectExpression.getAlias() is null.
*/
public void setSelectExpression(SelectExpression selectExpression) throws SemanticException {
if ( selectExpression == null || selectExpression.getAlias() == null ) {
throw new SemanticException( "A ResultVariableRefNode must refer to a non-null alias." );
}
this.selectExpression = selectExpression;
}
/**
* {@inheritDoc}
*/
@Override
public String getRenderText(SessionFactoryImplementor sessionFactory) {
int scalarColumnIndex = selectExpression.getScalarColumnIndex();
if ( scalarColumnIndex < 0 ) {
throw new IllegalStateException(
"selectExpression.getScalarColumnIndex() must be >= 0; actual = " + scalarColumnIndex
);
}
return sessionFactory.getDialect().replaceResultVariableInOrderByClauseWithPosition() ?
getColumnPositionsString( scalarColumnIndex ) :
getColumnNamesString( scalarColumnIndex );
}
private String getColumnPositionsString(int scalarColumnIndex ) {
int startPosition = getWalker().getSelectClause().getColumnNamesStartPosition( scalarColumnIndex );
StringBuffer buf = new StringBuffer();
int nColumns = getWalker().getSelectClause().getColumnNames()[ scalarColumnIndex ].length;
for ( int i = startPosition; i < startPosition + nColumns; i++ ) {
if ( i > startPosition ) {
buf.append( ", " );
}
buf.append( i );
}
return buf.toString();
}
private String getColumnNamesString(int scalarColumnIndex) {
return StringHelper.join( ", ", getWalker().getSelectClause().getColumnNames()[scalarColumnIndex] );
}
}