pdbench/census/DataNoise/src/DBConnector.java

import java.sql.*;
import java.util.ArrayList;

public class DBConnector
{
	private String mappingSchema = "Relation text, TID int4, Col text, CID text, HID text";
	private String compSchema = "CID text, HID text, WID text, Value int";
	private String worldSchema = "CID text, WID text";
	
	private String mappingAttrs = "Relation, TID, Col, CID, HID";
	private String compAttrs = "CID, HID, WID, Value";
	private String worldAttrs = "CID, WID";
	
	private static int id = 1;
	private Connection dbConnection;
	private Statement sqlStatement;
	
	private String templateRelName;
	private String mappingRelName;
	private String compRelName;
	private String worldRelName;
	
	public double worldCount;
	
	public DBConnector(String aDatabase, String aUser, String aPassword,
			String aTemplateRelName, String aMappingRelName, String aCompRelName,
			String aWorldRelName)
	{
		templateRelName = aTemplateRelName;
		mappingRelName = aMappingRelName;
		compRelName = aCompRelName;
		worldRelName = aWorldRelName;
		worldCount = 1;
		init(aDatabase, aUser, aPassword);
	}
	
	private void init(String aDatabase, String aUser, String aPassword)
	{
		try
		{
			Class.forName("org.postgresql.Driver"); //load the driver

			String connString = "jdbc:postgresql:" + aDatabase;
			//System.out.println("Connecting to " + connString);
			dbConnection = DriverManager.getConnection(connString,
					aUser, aPassword);
			sqlStatement = dbConnection.createStatement();
			
			// Create mapping relation
			createTable(mappingRelName, mappingSchema);
			
			// Create component relation
			createTable(compRelName, compSchema);
			
			// Create world relation
			//createTable(worldRelName, worldSchema);
		}
		catch (SQLException e)
		{
			System.err.println("Could not connect to the database!");
			e.printStackTrace();
			return;
		}
		catch (ClassNotFoundException e)
		{
			System.err.println("Could not load database driver!");
			return;
		}
	}
	
	public void closeConnection()
	{
		try
		{
			sqlStatement.close();
			dbConnection.close();
		}
		catch (SQLException e)
		{
			// Ignore
			return;
		}
	}
	
	private void createTable(String aName, String aSchema)
		throws SQLException		
	{
		String sql = "CREATE TABLE " + aName + " (" + aSchema + ");";
		System.out.println(sql);
		//sqlStatement.executeUpdate(sql);
	}
	private String getValue(String aRelName, int aTid, String aColumnName)
		throws SQLException
	{
		String sql = "SELECT " + aColumnName + " FROM " + aRelName + " WHERE tid = " + aTid;
		ResultSet rs = sqlStatement.executeQuery(sql);
		if (rs.next())
		{
			if (rs.getObject(1) == null)
			{
				return "-1";
			}
			return rs.getString(1);
		}				
		return null;
	}
	
	private void setHole(int aTid, String aColumnName, ArrayList aHoleValues,
			StringBuffer aRBuffer, StringBuffer aFBuffer, StringBuffer aCBuffer)
		throws SQLException
	{		
		// Get current value of the specified column
		String value = getValue(templateRelName, aTid, aColumnName);
		
		if (value == null || value.equals("-1"))
		{
//			//System.err.print("+");
			return;
		}

		
		// Add the real value of the column if it is not among the generated values
		if (!aHoleValues.contains(value))
		{
			aHoleValues.add(value);
		}
		
		
		// Create a hole in the template relation
		String sql = "UPDATE " + templateRelName + " SET " + aColumnName + " = -1 " +
			" WHERE tid = " + aTid + ";";
		aRBuffer.append(sql);
		
		// Insert an entry for the new hole in the mapping relation
		String cid = "c" + id;
		String hid = "h" + id;
		String mappingEntry = templateRelName + "\t" + aTid + "\t" +
			aColumnName + "\t" + cid + "\t" + hid + "\n";
		
		//insertTuple(mappingRelName, mappingAttrs, mappingEntry, aFStatement);
		aFBuffer.append(mappingEntry);
		id++;
		
		// Insert values for the new hole in the component relation
		insertHoleValues(cid, hid, aColumnName, aHoleValues, aCBuffer);
	}
	
	private void insertHoleValues(String aCid, String aHid, String aColumnName, ArrayList aValues, StringBuffer aBuffer)
		throws SQLException
	{
		
		for (int i = 0; i < aValues.size(); ++i)
		{
			String wid = "w" + (i + 1);
			String compEntry = aCid + "\t" + aHid + "\t"
				+ wid + "\t" + aValues.get(i).toString() + "\n";
			aBuffer.append(compEntry);
			
			//insertTuple(compRelName, compAttrs, compEntry, aBuffer);		
		}
	}
	
	private void insertTuple(String aRelName, String aSchema, String aValues, Statement aStatement)
		throws SQLException
	{
		String sql = "INSERT INTO " + aRelName + " (" + aSchema +
			") VALUES (" + aValues + ")";
		aStatement.addBatch(sql);
	}
	
	private int getRelSize(String aRelName)
	{
		ResultSet rs;
		try
		{
			rs = sqlStatement.executeQuery("SELECT count(*) from " + aRelName);
		}
		catch (SQLException e)
		{
			System.err.println("Could not execute statement!");
			return 0;
		}
		
		try
		{
			rs.next();
			return (new Integer(rs.getString(1))).intValue();
		}
		catch (SQLException e)
		{
			System.err.println("Error getting the result!");
			return 0;
		}
	}
	
	public int getTemplateRelSize()
	{
		return getRelSize(templateRelName);
	}
	
	public void introduceNoise(ArrayList aHoles)
		throws SQLException
	{		
		StringBuffer rBuffer = new StringBuffer();
		StringBuffer fBuffer = new StringBuffer();
		StringBuffer cBuffer = new StringBuffer();
		
		int size = aHoles.size();
		int step = 1000;
		//System.err.println(size);
		
		int i = 0;
		for (; i < size;)
		{
			fBuffer.append("COPY " + mappingRelName + "(" + mappingAttrs + ") FROM stdin;\n");
			cBuffer.append("COPY " + compRelName + " FROM stdin;\n");
			int n = i + step;
			if (n > size)
			{
				n = size;
			}
			int j = i;
			for (; j < n; ++j)
			{
				Hole holeInfo = (Hole) aHoles.get(j);				
				setHole(holeInfo.tid, holeInfo.columnName, holeInfo.values, rBuffer, fBuffer, cBuffer);
			}
			//System.err.print(j + " ");
			
			fBuffer.append("\\.");
			cBuffer.append("\\.");
			
			System.out.println(rBuffer.toString());
			System.out.flush();
			System.out.println(fBuffer.toString());
			System.out.flush();
			System.out.println(cBuffer.toString());
			System.out.flush();
			//sqlStatement.executeUpdate(fBuffer.toString());
			//sqlStatement.executeUpdate(cBuffer.toString());			
			
			rBuffer.delete(0, rBuffer.length());
			fBuffer.delete(0, fBuffer.length());
			cBuffer.delete(0, cBuffer.length());
			
			i += step;			
		}
			
		//System.err.println(i);
//		rBuffer.close();
//		fStatement.close();
//		cStatement.close();
	}
	
	public void createWorldTable() throws SQLException
	{
		
		String sql = "CREATE TABLE " + worldRelName + " AS SELECT DISTINCT cid, wid FROM " + compRelName + ";";
		System.out.println(sql);
	}
}