net.sf.mongodb_jdbc_driver.ParserHelper Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of mongojdbcdriver Show documentation
JDBC driver for MongoDB
The newest version!
/*
 *  Copyright (C) 2012 Rob Manning
 *  [email protected]
 *  
 *  This file is part of MongoDB JDBC Driver.
 *
 *  MongoDB JDBC Driver is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  MongoDB JDBC Driver 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with MongoDB JDBC Driver.  If not, see .
 */

package net.sf.mongodb_jdbc_driver;

import java.io.ByteArrayInputStream;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.Vector;

import net.sf.mongodb_jdbc_driver.zql.ParseException;
import net.sf.mongodb_jdbc_driver.zql.ZDelete;
import net.sf.mongodb_jdbc_driver.zql.ZFromItem;
import net.sf.mongodb_jdbc_driver.zql.ZInsert;
import net.sf.mongodb_jdbc_driver.zql.ZQuery;
import net.sf.mongodb_jdbc_driver.zql.ZSelectItem;
import net.sf.mongodb_jdbc_driver.zql.ZUpdate;
import net.sf.mongodb_jdbc_driver.zql.ZqlParser;

public class ParserHelper
{

	private final ZqlParser zqlParser = new ZqlParser();
	
	public boolean isQueryWithJoin(String sql) throws ParseException
	{
		initParser(sql);
		ZQuery q = (ZQuery)zqlParser.readStatement();
		Vector v = q.getFrom();
		return (v.size() > 1);
	}

	public boolean isSelectQuery(String sql) throws ParseException
	{
		initParser(sql);
		return (zqlParser.readStatement() instanceof ZQuery);
	}
	
	public boolean isUpdateQuery(String sql) throws ParseException {
		initParser(sql);
		return (zqlParser.readStatement() instanceof ZUpdate);
	}

	public boolean isInsertQuery(String sql) throws ParseException {
		initParser(sql);
		return (zqlParser.readStatement() instanceof ZInsert);
	}
	
	public boolean isDeleteQuery(String sql) throws ParseException {
		initParser(sql);
		return (zqlParser.readStatement() instanceof ZDelete);
	}

 	public String getSelectTable(String sql) throws ParseException, SQLException
	{
 		initParser(sql);
		ZQuery q = (ZQuery)zqlParser.readStatement();
		Vector v = q.getFrom();
		if (v.size() > 1) {
			throw new SQLException("MongoDB does not support queries with joins");
		}
		if (v.size() < 1) {
			throw new SQLException("The specified query ("+sql+") does not contain a from clause");
		}
		return ((ZFromItem) v.get(0)).getTable();
	}

 	public List getSelectColumns(String sql) throws ParseException, SQLException {
 		ArrayList result = new ArrayList();
		initParser(sql);
		ZQuery q = (ZQuery)zqlParser.readStatement();
		Vector v = q.getSelect();
		Enumeration e = v.elements();
		while (e.hasMoreElements()) {
			ZSelectItem selectElement = e.nextElement();
			if (selectElement.getAggregate() != null) {
				result.add(selectElement.getAggregate().toLowerCase() + "(" + selectElement.getColumn() + ")");
			} else {
				result.add(selectElement.getColumn().toLowerCase());
			}
		}
 		return result;
 	}
 	
 	private void initParser(String sql) {
 		if (sql.endsWith(";")) {
 			zqlParser.initParser(new ByteArrayInputStream(sql.getBytes()));
 		} else {
 			zqlParser.initParser(new ByteArrayInputStream((sql + ";").getBytes()));
 		}
 	}
 
}