ExistsNode.java

/*
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */
package org.teiid.translator.mongodb;

import org.teiid.logging.LogConstants;
import org.teiid.logging.LogManager;
import org.teiid.translator.TranslatorException;

import com.mongodb.BasicDBObject;
import com.mongodb.DBObject;
import com.mongodb.QueryBuilder;

/**
 * Represents a MERGED or EMBEDDED table's existence
 */
public class ExistsNode extends ProcessingNode {
    
    public ExistsNode(MongoDocument document) {
        super(document);
    }
    
    @Override
    public BasicDBObject getInstruction() throws TranslatorException {
        DBObject object = QueryBuilder.start(getDocumentName()).exists("true").notEquals(null).get(); //$NON-NLS-1$
        LogManager.logDetail(LogConstants.CTX_CONNECTOR, "{\"$match\": {"+object.toString()+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
        return new BasicDBObject("$match", object); //$NON-NLS-1$ 
    }
}