/*****************************************************************
* 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
* under the License.
****************************************************************/
package org.apache.cayenne.dba.openbase;
import java.io.IOException;
import java.util.List;
import org.apache.cayenne.access.trans.JoinStack;
import org.apache.cayenne.access.trans.JoinTreeNode;
import org.apache.cayenne.map.DbEntity;
import org.apache.cayenne.map.DbJoin;
import org.apache.cayenne.map.DbRelationship;
/**
* OpenBase does not support standard JOIN keyword and have strange syntax for defining
* inner/outer joins
*
* @see http://www.openbase.com/help/KnowledgeBase/400_OpenBaseSQL/401_SelectStatements.html
*/
public class OpenBaseJoinStack extends JoinStack {
public OpenBaseJoinStack() {
super();
}
@Override
protected void appendJoinSubtree(Appendable out, JoinTreeNode node)
throws IOException {
DbRelationship relationship = node.getRelationship();
if (relationship == null) {
return;
}
DbEntity targetEntity = (DbEntity) relationship.getTargetEntity();
String targetAlias = node.getTargetTableAlias();
out.append(", ").append(targetEntity.getFullyQualifiedName()).append(' ').append(
targetAlias);
for (JoinTreeNode child : node.getChildren()) {
appendJoinSubtree(out, child);
}
}
@Override
protected void appendQualifier(Appendable out, boolean firstQualifyerElement) throws IOException {
boolean first = firstQualifyerElement;
for (JoinTreeNode node : rootNode.getChildren()) {
if (!first) {
out.append(" AND ");
}
appendQualifierSubtree(out, node);
first = false;
}
}
protected void appendQualifierSubtree(Appendable out, JoinTreeNode node)
throws IOException {
DbRelationship relationship = node.getRelationship();
String srcAlias = node.getSourceTableAlias();
String targetAlias = node.getTargetTableAlias();
List<DbJoin> joins = relationship.getJoins();
int len = joins.size();
for (int i = 0; i < len; i++) {
DbJoin join = joins.get(i);
if (i > 0) {
out.append(" AND ");
}
out.append(srcAlias).append('.').append(join.getSourceName());
switch (node.getJoinType()) {
case INNER:
out.append(" = ");
break;
case LEFT_OUTER:
out.append(" * ");
break;
default:
throw new IllegalArgumentException("Unsupported join type: "
+ node.getJoinType());
}
out.append(targetAlias).append('.').append(join.getTargetName());
}
for (JoinTreeNode child : node.getChildren()) {
out.append(" AND ");
appendQualifierSubtree(out, child);
}
}
}