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* 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.translator.ejbql;
import java.util.Collection;
import org.apache.cayenne.ejbql.EJBQLBaseVisitor;
import org.apache.cayenne.ejbql.EJBQLException;
import org.apache.cayenne.ejbql.EJBQLExpression;
import org.apache.cayenne.ejbql.EJBQLExpressionVisitor;
import org.apache.cayenne.ejbql.parser.EJBQLAggregateColumn;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.map.ObjAttribute;
import org.apache.cayenne.map.ObjEntity;
import org.apache.cayenne.map.ObjRelationship;
/**
* @since 3.0
*/
class EJBQLAggregateColumnTranslator extends EJBQLBaseVisitor {
private EJBQLTranslationContext context;
private String attributeType;
EJBQLAggregateColumnTranslator(EJBQLTranslationContext context) {
this.context = context;
}
@Override
public boolean visitCount(EJBQLAggregateColumn expression) {
visitAggregateColumn(expression, new CountColumnVisitor());
return false;
}
@Override
public boolean visitAverage(EJBQLAggregateColumn expression) {
visitAggregateColumn(expression, new FieldPathTranslator());
return false;
}
@Override
public boolean visitMax(EJBQLAggregateColumn expression) {
visitAggregateColumn(expression, new FieldPathTranslator());
return false;
}
@Override
public boolean visitMin(EJBQLAggregateColumn expression) {
visitAggregateColumn(expression, new FieldPathTranslator());
return false;
}
@Override
public boolean visitSum(EJBQLAggregateColumn expression) {
visitAggregateColumn(expression, new FieldPathTranslator());
return false;
}
private void visitAggregateColumn(EJBQLAggregateColumn column, EJBQLExpressionVisitor pathVisitor) {
if (context.isAppendingResultColumns()) {
context.append(" #result('");
} else {
context.append(' ');
}
context.append(column.getFunction()).append('(');
// path visitor must set attributeType ivar
column.visit(pathVisitor);
context.append(')');
if (context.isAppendingResultColumns()) {
context.append("' '").append(column.getJavaType(attributeType)).append("' '")
.append(context.nextColumnAlias()).append("')");
}
}
class FieldPathTranslator extends EJBQLPathTranslator {
FieldPathTranslator() {
super(EJBQLAggregateColumnTranslator.this.context);
}
@Override
public boolean visitDistinct(EJBQLExpression expression) {
context.append("DISTINCT ");
return true;
}
@Override
protected void appendMultiColumnPath(EJBQLMultiColumnOperand operand) {
throw new EJBQLException("Can't use multi-column paths in column clause");
}
@Override
protected void processTerminatingAttribute(ObjAttribute attribute) {
EJBQLAggregateColumnTranslator.this.attributeType = attribute.getType();
DbEntity table = currentEntity.getDbEntity();
String alias = this.lastAlias != null ? lastAlias : context.getTableAlias(idPath, context
.getQuotingStrategy().quotedFullyQualifiedName(table));
context.append(alias).append('.')
.append(context.getQuotingStrategy().quotedName(attribute.getDbAttribute()));
}
@Override
protected void processTerminatingRelationship(ObjRelationship relationship) {
Collection<DbAttribute> dbAttr = ((ObjEntity) relationship.getTargetEntity()).getDbEntity().getAttributes();
if (dbAttr.size() > 0) {
resolveJoin();
}
context.append('*');
}
}
class CountColumnVisitor extends EJBQLBaseVisitor {
@Override
public boolean visitDistinct(EJBQLExpression expression) {
context.append("DISTINCT ");
return true;
}
@Override
public boolean visitIdentifier(EJBQLExpression expression) {
context.append('*');
return false;
}
@Override
public boolean visitPath(EJBQLExpression expression, int finishedChildIndex) {
expression.visit(new FieldPathTranslator());
return false;
}
}
}