/*****************************************************************
* 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.access.trans;
import java.io.IOException;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Iterator;
import org.apache.cayenne.dba.DbAdapter;
import org.apache.cayenne.dba.QuotingStrategy;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.query.BatchQuery;
import org.apache.cayenne.query.DeleteBatchQuery;
/**
* Translator for delete BatchQueries. Creates parameterized DELETE SQL
* statements.
*/
public class DeleteBatchQueryBuilder extends BatchQueryBuilder {
public DeleteBatchQueryBuilder(DbAdapter adapter) {
super(adapter);
}
@Override
public String createSqlString(BatchQuery batch) throws IOException {
QuotingStrategy strategy = getAdapter().getQuotingStrategy();
StringBuffer query = new StringBuffer("DELETE FROM ");
query.append(strategy.quotedFullyQualifiedName(batch.getDbEntity()));
applyQualifier(query, batch);
return query.toString();
}
/**
* Appends WHERE clause to SQL string
*/
protected void applyQualifier(StringBuffer query, BatchQuery batch) {
query.append(" WHERE ");
DeleteBatchQuery deleteBatch = (DeleteBatchQuery) batch;
Iterator<DbAttribute> i = deleteBatch.getQualifierAttributes().iterator();
while (i.hasNext()) {
DbAttribute attribute = i.next();
appendDbAttribute(query, attribute);
query.append(deleteBatch.isNull(attribute) ? " IS NULL" : " = ?");
if (i.hasNext()) {
query.append(" AND ");
}
}
}
/**
* Binds BatchQuery parameters to the PreparedStatement.
*/
@Override
public void bindParameters(PreparedStatement statement, BatchQuery query) throws SQLException, Exception {
DeleteBatchQuery deleteBatch = (DeleteBatchQuery) query;
int parameterIndex = getFirstParameterIndex(query);
int i = 0;
for (DbAttribute attribute : deleteBatch.getQualifierAttributes()) {
Object value = query.getValue(i++);
// skip null attributes... they are translated as "IS NULL"
if (deleteBatch.isNull(attribute)) {
continue;
}
adapter.bindParameter(statement, value, parameterIndex++, attribute.getType(), attribute.getScale());
}
}
/**
* @return index of first parameter in delete clause
*/
protected int getFirstParameterIndex(BatchQuery query) {
return 1;
}
}