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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
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package org.apache.cayenne.access.jdbc;
import java.io.IOException;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Types;
import org.apache.cayenne.access.trans.DeleteBatchQueryBuilder;
import org.apache.cayenne.dba.DbAdapter;
import org.apache.cayenne.dba.QuotingStrategy;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.query.BatchQuery;
/**
* Implementation of {@link DeleteBatchQueryBuilder}, which uses 'soft' delete
* (runs UPDATE and sets 'deleted' field to true instead-of running SQL DELETE)
*/
public class SoftDeleteBatchQueryBuilder extends DeleteBatchQueryBuilder {
private String deletedFieldName;
public SoftDeleteBatchQueryBuilder(DbAdapter adapter, String deletedFieldName) {
super(adapter);
this.deletedFieldName = deletedFieldName;
}
@Override
public String createSqlString(BatchQuery batch) throws IOException {
if (!needSoftDelete(batch)) {
return super.createSqlString(batch);
}
QuotingStrategy strategy = getAdapter().getQuotingStrategy();
StringBuffer query = new StringBuffer("UPDATE ");
query.append(strategy.quotedFullyQualifiedName(batch.getDbEntity()));
query.append(" SET ").append(strategy.quotedIdentifier(batch.getDbEntity(), deletedFieldName)).append(" = ?");
applyQualifier(query, batch);
return query.toString();
}
@Override
protected int getFirstParameterIndex(BatchQuery query) {
return needSoftDelete(query) ? 2 : 1;
}
@Override
public void bindParameters(PreparedStatement statement, BatchQuery query) throws SQLException, Exception {
if (needSoftDelete(query)) {
// binding first parameter (which is 'deleted') as true
adapter.bindParameter(statement, true, 1, Types.BOOLEAN, -1);
}
super.bindParameters(statement, query);
}
/**
* @return whether 'soft' deletion should be used
*/
protected boolean needSoftDelete(BatchQuery query) {
DbAttribute attr = (DbAttribute) query.getDbEntity().getAttribute(deletedFieldName);
return attr != null && attr.getType() == Types.BOOLEAN;
}
}