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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
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package org.apache.cayenne.access.jdbc;
import org.apache.cayenne.ejbql.EJBQLBaseVisitor;
import org.apache.cayenne.ejbql.EJBQLException;
import org.apache.cayenne.ejbql.EJBQLExpression;
import org.apache.cayenne.ejbql.EJBQLExpressionVisitor;
/**
* @since 3.0
*/
class EJBQLOrderByTranslator extends EJBQLBaseVisitor {
private EJBQLTranslationContext context;
private int itemCount;
EJBQLOrderByTranslator(EJBQLTranslationContext context) {
this.context = context;
}
@Override
public boolean visitOrderByItem(EJBQLExpression expression) {
if (itemCount++ > 0) {
context.append(',');
}
return true;
}
@Override
public boolean visitDescending(EJBQLExpression expression) {
context.append(" DESC");
return true;
}
@Override
public boolean visitPath(EJBQLExpression expression, int finishedChildIndex) {
EJBQLExpressionVisitor childVisitor = new EJBQLPathTranslator(context) {
@Override
protected void appendMultiColumnPath(EJBQLMultiColumnOperand operand) {
throw new EJBQLException("Can't order on multi-column paths or objects");
}
};
expression.visit(childVisitor);
return false;
}
}