package org.postgresql.jdbc2;

// IMPORTANT NOTE: This file implements the JDBC 2 version of the driver.
// If you make any modifications to this file, you must make sure that the
// changes are also made (if relevent) to the related JDBC 1 class in the
// org.postgresql.jdbc1 package.

import java.lang.*;
import java.io.*;
import java.math.*;
import java.text.*;
import java.util.*;
import java.sql.*;
import org.postgresql.Field;
import org.postgresql.largeobject.*;
import org.postgresql.util.*;
import org.postgresql.core.Encoding;

/**
 * A ResultSet provides access to a table of data generated by executing a
 * Statement.  The table rows are retrieved in sequence.  Within a row its
 * column values can be accessed in any order.
 *
 * <P>A ResultSet maintains a cursor pointing to its current row of data.
 * Initially the cursor is positioned before the first row.  The 'next'
 * method moves the cursor to the next row.
 *
 * <P>The getXXX methods retrieve column values for the current row.  You can
 * retrieve values either using the index number of the column, or by using
 * the name of the column.	In general using the column index will be more
 * efficient.  Columns are numbered from 1.
 *
 * <P>For maximum portability, ResultSet columns within each row should be read
 * in left-to-right order and each column should be read only once.
 *
 *<P> For the getXXX methods, the JDBC driver attempts to convert the
 * underlying data to the specified Java type and returns a suitable Java
 * value.  See the JDBC specification for allowable mappings from SQL types
 * to Java types with the ResultSet getXXX methods.
 *
 * <P>Column names used as input to getXXX methods are case insenstive.  When
 * performing a getXXX using a column name, if several columns have the same
 * name, then the value of the first matching column will be returned.	The
 * column name option is designed to be used when column names are used in the
 * SQL Query.  For columns that are NOT explicitly named in the query, it is
 * best to use column numbers.	If column names were used there is no way for
 * the programmer to guarentee that they actually refer to the intended
 * columns.
 *
 * <P>A ResultSet is automatically closed by the Statement that generated it
 * when that Statement is closed, re-executed, or is used to retrieve the
 * next result from a sequence of multiple results.
 *
 * <P>The number, types and properties of a ResultSet's columns are provided by
 * the ResultSetMetaData object returned by the getMetaData method.
 *
 * @see ResultSetMetaData
 * @see java.sql.ResultSet
 */
public class ResultSet extends org.postgresql.ResultSet implements java.sql.ResultSet
{
	protected org.postgresql.jdbc2.Statement statement;

	private StringBuffer sbuf = null;

	/**
	 * Create a new ResultSet - Note that we create ResultSets to
	 * represent the results of everything.
	 *
	 * @param fields an array of Field objects (basically, the
	 *	ResultSet MetaData)
	 * @param tuples Vector of the actual data
	 * @param status the status string returned from the back end
	 * @param updateCount the number of rows affected by the operation
	 * @param cursor the positioned update/delete cursor name
	 */
	public ResultSet(Connection conn, Field[] fields, Vector tuples, String status, int updateCount, int insertOID, boolean binaryCursor)
	{
		super(conn, fields, tuples, status, updateCount, insertOID, binaryCursor);
	}

	/**
	 * Create a new ResultSet - Note that we create ResultSets to
	 * represent the results of everything.
	 *
	 * @param fields an array of Field objects (basically, the
	 *	ResultSet MetaData)
	 * @param tuples Vector of the actual data
	 * @param status the status string returned from the back end
	 * @param updateCount the number of rows affected by the operation
	 * @param cursor the positioned update/delete cursor name
	 */
	public ResultSet(Connection conn, Field[] fields, Vector tuples, String status, int updateCount)
	{
		super(conn, fields, tuples, status, updateCount, 0, false);
	}

	/**
	 * A ResultSet is initially positioned before its first row,
	 * the first call to next makes the first row the current row;
	 * the second call makes the second row the current row, etc.
	 *
	 * <p>If an input stream from the previous row is open, it is
	 * implicitly closed.  The ResultSet's warning chain is cleared
	 * when a new row is read
	 *
	 * @return true if the new current is valid; false if there are no
	 *	more rows
	 * @exception SQLException if a database access error occurs
	 */
	public boolean next() throws SQLException
	{
		if (++current_row >= rows.size())
			return false;
		this_row = (byte [][])rows.elementAt(current_row);
		return true;
	}

	/**
	 * In some cases, it is desirable to immediately release a ResultSet
	 * database and JDBC resources instead of waiting for this to happen
	 * when it is automatically closed.  The close method provides this
	 * immediate release.
	 *
	 * <p><B>Note:</B> A ResultSet is automatically closed by the Statement
	 * the Statement that generated it when that Statement is closed,
	 * re-executed, or is used to retrieve the next result from a sequence
	 * of multiple results.  A ResultSet is also automatically closed
	 * when it is garbage collected.
	 *
	 * @exception SQLException if a database access error occurs
	 */
	public void close() throws SQLException
	{
		//release resources held (memory for tuples)
		if (rows != null)
		{
			rows = null;
		}
	}

	/**
	 * A column may have the value of SQL NULL; wasNull() reports whether
	 * the last column read had this special value.  Note that you must
	 * first call getXXX on a column to try to read its value and then
	 * call wasNull() to find if the value was SQL NULL
	 *
	 * @return true if the last column read was SQL NULL
	 * @exception SQLException if a database access error occurred
	 */
	public boolean wasNull() throws SQLException
	{
		return wasNullFlag;
	}

	/**
	 * Get the value of a column in the current row as a Java String
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return the column value, null for SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public String getString(int columnIndex) throws SQLException
	{
		if (columnIndex < 1 || columnIndex > fields.length)
			throw new PSQLException("postgresql.res.colrange");

		wasNullFlag = (this_row[columnIndex - 1] == null);
		if (wasNullFlag)
			return null;

		Encoding encoding = connection.getEncoding();
		return encoding.decode(this_row[columnIndex - 1]);
	}

	/**
	 * Get the value of a column in the current row as a Java boolean
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return the column value, false for SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public boolean getBoolean(int columnIndex) throws SQLException
	{
		return toBoolean( getString(columnIndex) );
	}

	/**
	 * Get the value of a column in the current row as a Java byte.
	 *
	 * @param columnIndex the first column is 1, the second is 2,...
	 * @return the column value; 0 if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public byte getByte(int columnIndex) throws SQLException
	{
		String s = getString(columnIndex);

		if (s != null)
		{
			try
			{
				return Byte.parseByte(s);
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException("postgresql.res.badbyte", s);
			}
		}
		return 0;		// SQL NULL
	}

	/**
	 * Get the value of a column in the current row as a Java short.
	 *
	 * @param columnIndex the first column is 1, the second is 2,...
	 * @return the column value; 0 if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public short getShort(int columnIndex) throws SQLException
	{
		String s = getFixedString(columnIndex);

		if (s != null)
		{
			try
			{
				return Short.parseShort(s);
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException("postgresql.res.badshort", s);
			}
		}
		return 0;		// SQL NULL
	}

	/**
	 * Get the value of a column in the current row as a Java int.
	 *
	 * @param columnIndex the first column is 1, the second is 2,...
	 * @return the column value; 0 if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public int getInt(int columnIndex) throws SQLException
	{
		return toInt( getFixedString(columnIndex) );
	}

	/**
	 * Get the value of a column in the current row as a Java long.
	 *
	 * @param columnIndex the first column is 1, the second is 2,...
	 * @return the column value; 0 if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public long getLong(int columnIndex) throws SQLException
	{
		return toLong( getFixedString(columnIndex) );
	}

	/**
	 * Get the value of a column in the current row as a Java float.
	 *
	 * @param columnIndex the first column is 1, the second is 2,...
	 * @return the column value; 0 if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public float getFloat(int columnIndex) throws SQLException
	{
		return toFloat( getFixedString(columnIndex) );
	}

	/**
	 * Get the value of a column in the current row as a Java double.
	 *
	 * @param columnIndex the first column is 1, the second is 2,...
	 * @return the column value; 0 if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public double getDouble(int columnIndex) throws SQLException
	{
		return toDouble( getFixedString(columnIndex) );
	}

	/**
	 * Get the value of a column in the current row as a
	 * java.math.BigDecimal object
	 *
	 * @param columnIndex  the first column is 1, the second is 2...
	 * @param scale the number of digits to the right of the decimal
	 * @return the column value; if the value is SQL NULL, null
	 * @exception SQLException if a database access error occurs
	 * @deprecated
	 */
	public BigDecimal getBigDecimal(int columnIndex, int scale) throws SQLException
	{
		return toBigDecimal( getFixedString(columnIndex), scale );
	}

	/**
	 * Get the value of a column in the current row as a Java byte array.
	 *
	 * <p>In normal use, the bytes represent the raw values returned by the
	 * backend. However, if the column is an OID, then it is assumed to
	 * refer to a Large Object, and that object is returned as a byte array.
	 *
	 * <p><b>Be warned</b> If the large object is huge, then you may run out
	 * of memory.
	 *
	 * @param columnIndex the first column is 1, the second is 2, ...
	 * @return the column value; if the value is SQL NULL, the result
	 *	is null
	 * @exception SQLException if a database access error occurs
	 */
	public byte[] getBytes(int columnIndex) throws SQLException
	{
		if (columnIndex < 1 || columnIndex > fields.length)
			throw new PSQLException("postgresql.res.colrange");

		//If the data is already binary then just return it
		if (binaryCursor)
			return this_row[columnIndex - 1];

		if (connection.haveMinimumCompatibleVersion("7.2"))
		{
			//Version 7.2 supports the bytea datatype for byte arrays
			return PGbytea.toBytes(getString(columnIndex));
		}
		else
		{
			//Version 7.1 and earlier supports LargeObjects for byte arrays
			wasNullFlag = (this_row[columnIndex - 1] == null);
			// Handle OID's as BLOBS
			if (!wasNullFlag)
			{
				if ( fields[columnIndex - 1].getOID() == 26)
				{
					LargeObjectManager lom = connection.getLargeObjectAPI();
					LargeObject lob = lom.open(getInt(columnIndex));
					byte buf[] = lob.read(lob.size());
					lob.close();
					return buf;
				}
			}
		}
		return null;
	}

	/**
	 * Get the value of a column in the current row as a java.sql.Date
	 * object
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return the column value; null if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public java.sql.Date getDate(int columnIndex) throws SQLException
	{
		return toDate( getString(columnIndex) );
	}

	/**
	 * Get the value of a column in the current row as a java.sql.Time
	 * object
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return the column value; null if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public Time getTime(int columnIndex) throws SQLException
	{
		return toTime( getString(columnIndex) );
	}

	/**
	 * Get the value of a column in the current row as a
	 * java.sql.Timestamp object
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return the column value; null if SQL NULL
	 * @exception SQLException if a database access error occurs
	 */
	public Timestamp getTimestamp(int columnIndex) throws SQLException
	{
		return toTimestamp( getString(columnIndex), this );
	}

	/**
	 * A column value can be retrieved as a stream of ASCII characters
	 * and then read in chunks from the stream.  This method is
	 * particular suitable for retrieving large LONGVARCHAR values.
	 * The JDBC driver will do any necessary conversion from the
	 * database format into ASCII.
	 *
	 * <p><B>Note:</B> All the data in the returned stream must be read
	 * prior to getting the value of any other column.	The next call
	 * to a get method implicitly closes the stream.  Also, a stream
	 * may return 0 for available() whether there is data available
	 * or not.
	 *
	 *<p> We implement an ASCII stream as a Binary stream - we should really
	 * do the data conversion, but I cannot be bothered to implement this
	 * right now.
	 *
	 * @param columnIndex the first column is 1, the second is 2, ...
	 * @return a Java InputStream that delivers the database column
	 *	value as a stream of one byte ASCII characters.  If the
	 *	value is SQL NULL then the result is null
	 * @exception SQLException if a database access error occurs
	 * @see getBinaryStream
	 */
	public InputStream getAsciiStream(int columnIndex) throws SQLException
	{
		wasNullFlag = (this_row[columnIndex - 1] == null);
		if (wasNullFlag)
			return null;

		if (connection.haveMinimumCompatibleVersion("7.2"))
		{
			//Version 7.2 supports AsciiStream for all the PG text types
			//As the spec/javadoc for this method indicate this is to be used for
			//large text values (i.e. LONGVARCHAR)	PG doesn't have a separate
			//long string datatype, but with toast the text datatype is capable of
			//handling very large values.  Thus the implementation ends up calling
			//getString() since there is no current way to stream the value from the server
			try
			{
				return new ByteArrayInputStream(getString(columnIndex).getBytes("ASCII"));
			}
			catch (UnsupportedEncodingException l_uee)
			{
				throw new PSQLException("postgresql.unusual", l_uee);
			}
		}
		else
		{
			// In 7.1 Handle as BLOBS so return the LargeObject input stream
			return getBinaryStream(columnIndex);
		}
	}

	/**
	 * A column value can also be retrieved as a stream of Unicode
	 * characters. We implement this as a binary stream.
	 *
	 * ** DEPRECATED IN JDBC 2 **
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return a Java InputStream that delivers the database column value
	 *	as a stream of two byte Unicode characters.  If the value is
	 *	SQL NULL, then the result is null
	 * @exception SQLException if a database access error occurs
	 * @see getAsciiStream
	 * @see getBinaryStream
	 * @deprecated in JDBC2.0
	 */
	public InputStream getUnicodeStream(int columnIndex) throws SQLException
	{
		wasNullFlag = (this_row[columnIndex - 1] == null);
		if (wasNullFlag)
			return null;

		if (connection.haveMinimumCompatibleVersion("7.2"))
		{
			//Version 7.2 supports AsciiStream for all the PG text types
			//As the spec/javadoc for this method indicate this is to be used for
			//large text values (i.e. LONGVARCHAR)	PG doesn't have a separate
			//long string datatype, but with toast the text datatype is capable of
			//handling very large values.  Thus the implementation ends up calling
			//getString() since there is no current way to stream the value from the server
			try
			{
				return new ByteArrayInputStream(getString(columnIndex).getBytes("UTF-8"));
			}
			catch (UnsupportedEncodingException l_uee)
			{
				throw new PSQLException("postgresql.unusual", l_uee);
			}
		}
		else
		{
			// In 7.1 Handle as BLOBS so return the LargeObject input stream
			return getBinaryStream(columnIndex);
		}
	}

	/**
	 * A column value can also be retrieved as a binary strea.	This
	 * method is suitable for retrieving LONGVARBINARY values.
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return a Java InputStream that delivers the database column value
	 * as a stream of bytes.  If the value is SQL NULL, then the result
	 * is null
	 * @exception SQLException if a database access error occurs
	 * @see getAsciiStream
	 * @see getUnicodeStream
	 */
	public InputStream getBinaryStream(int columnIndex) throws SQLException
	{
		wasNullFlag = (this_row[columnIndex - 1] == null);
		if (wasNullFlag)
			return null;

		if (connection.haveMinimumCompatibleVersion("7.2"))
		{
			//Version 7.2 supports BinaryStream for all PG bytea type
			//As the spec/javadoc for this method indicate this is to be used for
			//large binary values (i.e. LONGVARBINARY)	PG doesn't have a separate
			//long binary datatype, but with toast the bytea datatype is capable of
			//handling very large values.  Thus the implementation ends up calling
			//getBytes() since there is no current way to stream the value from the server
			byte b[] = getBytes(columnIndex);
			if (b != null)
				return new ByteArrayInputStream(b);
		}
		else
		{
			// In 7.1 Handle as BLOBS so return the LargeObject input stream
			if ( fields[columnIndex - 1].getOID() == 26)
			{
				LargeObjectManager lom = connection.getLargeObjectAPI();
				LargeObject lob = lom.open(getInt(columnIndex));
				return lob.getInputStream();
			}
		}
		return null;
	}

	/**
	 * The following routines simply convert the columnName into
	 * a columnIndex and then call the appropriate routine above.
	 *
	 * @param columnName is the SQL name of the column
	 * @return the column value
	 * @exception SQLException if a database access error occurs
	 */
	public String getString(String columnName) throws SQLException
	{
		return getString(findColumn(columnName));
	}

	public boolean getBoolean(String columnName) throws SQLException
	{
		return getBoolean(findColumn(columnName));
	}

	public byte getByte(String columnName) throws SQLException
	{

		return getByte(findColumn(columnName));
	}

	public short getShort(String columnName) throws SQLException
	{
		return getShort(findColumn(columnName));
	}

	public int getInt(String columnName) throws SQLException
	{
		return getInt(findColumn(columnName));
	}

	public long getLong(String columnName) throws SQLException
	{
		return getLong(findColumn(columnName));
	}

	public float getFloat(String columnName) throws SQLException
	{
		return getFloat(findColumn(columnName));
	}

	public double getDouble(String columnName) throws SQLException
	{
		return getDouble(findColumn(columnName));
	}

	/**
	 * @deprecated
	 */
	public BigDecimal getBigDecimal(String columnName, int scale) throws SQLException
	{
		return getBigDecimal(findColumn(columnName), scale);
	}

	public byte[] getBytes(String columnName) throws SQLException
	{
		return getBytes(findColumn(columnName));
	}

	public java.sql.Date getDate(String columnName) throws SQLException
	{
		return getDate(findColumn(columnName));
	}

	public Time getTime(String columnName) throws SQLException
	{
		return getTime(findColumn(columnName));
	}

	public Timestamp getTimestamp(String columnName) throws SQLException
	{
		return getTimestamp(findColumn(columnName));
	}

	public InputStream getAsciiStream(String columnName) throws SQLException
	{
		return getAsciiStream(findColumn(columnName));
	}

	/**
	 *
	 * ** DEPRECATED IN JDBC 2 **
	 *
	 * @deprecated
	 */
	public InputStream getUnicodeStream(String columnName) throws SQLException
	{
		return getUnicodeStream(findColumn(columnName));
	}

	public InputStream getBinaryStream(String columnName) throws SQLException
	{
		return getBinaryStream(findColumn(columnName));
	}

	/**
	 * The first warning reported by calls on this ResultSet is
	 * returned.  Subsequent ResultSet warnings will be chained
	 * to this SQLWarning.
	 *
	 * <p>The warning chain is automatically cleared each time a new
	 * row is read.
	 *
	 * <p><B>Note:</B> This warning chain only covers warnings caused by
	 * ResultSet methods.  Any warnings caused by statement methods
	 * (such as reading OUT parameters) will be chained on the
	 * Statement object.
	 *
	 * @return the first SQLWarning or null;
	 * @exception SQLException if a database access error occurs.
	 */
	public SQLWarning getWarnings() throws SQLException
	{
		return warnings;
	}

	/**
	 * After this call, getWarnings returns null until a new warning
	 * is reported for this ResultSet
	 *
	 * @exception SQLException if a database access error occurs
	 */
	public void clearWarnings() throws SQLException
	{
		warnings = null;
	}

	/**
	 * Get the name of the SQL cursor used by this ResultSet
	 *
	 * <p>In SQL, a result table is retrieved though a cursor that is
	 * named.  The current row of a result can be updated or deleted
	 * using a positioned update/delete statement that references
	 * the cursor name.
	 *
	 * <p>JDBC supports this SQL feature by providing the name of the
	 * SQL cursor used by a ResultSet.	The current row of a ResulSet
	 * is also the current row of this SQL cursor.
	 *
	 * <p><B>Note:</B> If positioned update is not supported, a SQLException
	 * is thrown.
	 *
	 * @return the ResultSet's SQL cursor name.
	 * @exception SQLException if a database access error occurs
	 */
	public String getCursorName() throws SQLException
	{
		return connection.getCursorName();
	}

	/**
	 * The numbers, types and properties of a ResultSet's columns are
	 * provided by the getMetaData method
	 *
	 * @return a description of the ResultSet's columns
	 * @exception SQLException if a database access error occurs
	 */
	public java.sql.ResultSetMetaData getMetaData() throws SQLException
	{
		return new ResultSetMetaData(rows, fields);
	}

	/**
	 * Get the value of a column in the current row as a Java object
	 *
	 * <p>This method will return the value of the given column as a
	 * Java object.  The type of the Java object will be the default
	 * Java Object type corresponding to the column's SQL type, following
	 * the mapping specified in the JDBC specification.
	 *
	 * <p>This method may also be used to read database specific abstract
	 * data types.
	 *
	 * @param columnIndex the first column is 1, the second is 2...
	 * @return a Object holding the column value
	 * @exception SQLException if a database access error occurs
	 */
	public Object getObject(int columnIndex) throws SQLException
	{
		Field field;

		if (columnIndex < 1 || columnIndex > fields.length)
			throw new PSQLException("postgresql.res.colrange");

		wasNullFlag = (this_row[columnIndex - 1] == null);
		if (wasNullFlag)
			return null;

		field = fields[columnIndex - 1];

		// some fields can be null, mainly from those returned by MetaData methods
		if (field == null)
		{
			wasNullFlag = true;
			return null;
		}

		switch (field.getSQLType())
		{
		case Types.BIT:
			return new Boolean(getBoolean(columnIndex));
		case Types.SMALLINT:
			return new Integer(getInt(columnIndex));
		case Types.INTEGER:
			return new Integer(getInt(columnIndex));
		case Types.BIGINT:
			return new Long(getLong(columnIndex));
		case Types.NUMERIC:
			return getBigDecimal
				   (columnIndex, (field.getMod() == -1) ? -1 : ((field.getMod() - 4) & 0xffff));
		case Types.REAL:
			return new Float(getFloat(columnIndex));
		case Types.DOUBLE:
			return new Double(getDouble(columnIndex));
		case Types.CHAR:
		case Types.VARCHAR:
			return getString(columnIndex);
		case Types.DATE:
			return getDate(columnIndex);
		case Types.TIME:
			return getTime(columnIndex);
		case Types.TIMESTAMP:
			return getTimestamp(columnIndex);
		case Types.BINARY:
		case Types.VARBINARY:
			return getBytes(columnIndex);
		default:
			String type = field.getPGType();
			// if the backend doesn't know the type then coerce to String
			if (type.equals("unknown"))
			{
				return getString(columnIndex);
			}
			else
			{
				return connection.getObject(field.getPGType(), getString(columnIndex));
			}
		}
	}

	/**
	 * Get the value of a column in the current row as a Java object
	 *
	 *<p> This method will return the value of the given column as a
	 * Java object.  The type of the Java object will be the default
	 * Java Object type corresponding to the column's SQL type, following
	 * the mapping specified in the JDBC specification.
	 *
	 * <p>This method may also be used to read database specific abstract
	 * data types.
	 *
	 * @param columnName is the SQL name of the column
	 * @return a Object holding the column value
	 * @exception SQLException if a database access error occurs
	 */
	public Object getObject(String columnName) throws SQLException
	{
		return getObject(findColumn(columnName));
	}

	/**
	 * Map a ResultSet column name to a ResultSet column index
	 *
	 * @param columnName the name of the column
	 * @return the column index
	 * @exception SQLException if a database access error occurs
	 */
	public int findColumn(String columnName) throws SQLException
	{
		int i;

		final int flen = fields.length;
		for (i = 0 ; i < flen; ++i)
			if (fields[i].getName().equalsIgnoreCase(columnName))
				return (i + 1);
		throw new PSQLException ("postgresql.res.colname", columnName);
	}

	// ** JDBC 2 Extensions **

	public boolean absolute(int index) throws SQLException
	{
		// index is 1-based, but internally we use 0-based indices
		int internalIndex;

		if (index == 0)
			throw new SQLException("Cannot move to index of 0");

		final int rows_size = rows.size();

		//if index<0, count from the end of the result set, but check
		//to be sure that it is not beyond the first index
		if (index < 0)
			if (index >= -rows_size)
				internalIndex = rows_size + index;
			else
			{
				beforeFirst();
				return false;
			}

		//must be the case that index>0,
		//find the correct place, assuming that
		//the index is not too large
		if (index <= rows_size)
			internalIndex = index - 1;
		else
		{
			afterLast();
			return false;
		}

		current_row = internalIndex;
		this_row = (byte [][])rows.elementAt(internalIndex);
		return true;
	}

	public void afterLast() throws SQLException
	{
		final int rows_size = rows.size();
		if (rows_size > 0)
			current_row = rows_size;
	}

	public void beforeFirst() throws SQLException
	{
		if (rows.size() > 0)
			current_row = -1;
	}

	public void cancelRowUpdates() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void deleteRow() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public boolean first() throws SQLException
	{
		if (rows.size() <= 0)
			return false;
		current_row = 0;
		this_row = (byte [][])rows.elementAt(current_row);
		return true;
	}

	public java.sql.Array getArray(String colName) throws SQLException
	{
		return getArray(findColumn(colName));
	}

	public java.sql.Array getArray(int i) throws SQLException
	{
		wasNullFlag = (this_row[i - 1] == null);
		if (wasNullFlag)
			return null;

		if (i < 1 || i > fields.length)
			throw new PSQLException("postgresql.res.colrange");
		return (java.sql.Array) new org.postgresql.jdbc2.Array( connection, i, fields[i - 1], this );
	}

	public java.math.BigDecimal getBigDecimal(int columnIndex) throws SQLException
	{
		return getBigDecimal(columnIndex, -1);
	}

	public java.math.BigDecimal getBigDecimal(String columnName) throws SQLException
	{
		return getBigDecimal(findColumn(columnName));
	}

	public Blob getBlob(String columnName) throws SQLException
	{
		return getBlob(findColumn(columnName));
	}

	public Blob getBlob(int i) throws SQLException
	{
		return new org.postgresql.largeobject.PGblob(connection, getInt(i));
	}

	public java.io.Reader getCharacterStream(String columnName) throws SQLException
	{
		return getCharacterStream(findColumn(columnName));
	}

	public java.io.Reader getCharacterStream(int i) throws SQLException
	{
		wasNullFlag = (this_row[i - 1] == null);
		if (wasNullFlag)
			return null;

		if (connection.haveMinimumCompatibleVersion("7.2"))
		{
			//Version 7.2 supports AsciiStream for all the PG text types
			//As the spec/javadoc for this method indicate this is to be used for
			//large text values (i.e. LONGVARCHAR)	PG doesn't have a separate
			//long string datatype, but with toast the text datatype is capable of
			//handling very large values.  Thus the implementation ends up calling
			//getString() since there is no current way to stream the value from the server
			return new CharArrayReader(getString(i).toCharArray());
		}
		else
		{
			// In 7.1 Handle as BLOBS so return the LargeObject input stream
			Encoding encoding = connection.getEncoding();
			InputStream input = getBinaryStream(i);
			return encoding.getDecodingReader(input);
		}
	}

	/**
	 * New in 7.1
	 */
	public Clob getClob(String columnName) throws SQLException
	{
		return getClob(findColumn(columnName));
	}

	/**
	 * New in 7.1
	 */
	public Clob getClob(int i) throws SQLException
	{
		return new org.postgresql.largeobject.PGclob(connection, getInt(i));
	}

	public int getConcurrency() throws SQLException
	{
		// New in 7.1 - The standard ResultSet class will now return
		// CONCUR_READ_ONLY. A sub-class will overide this if the query was
		// updateable.
		return CONCUR_READ_ONLY;
	}

	public java.sql.Date getDate(int i, java.util.Calendar cal) throws SQLException
	{
		// new in 7.1: If I read the specs, this should use cal only if we don't
		// store the timezone, and if we do, then act just like getDate()?
		// for now...
		return getDate(i);
	}

	public Time getTime(int i, java.util.Calendar cal) throws SQLException
	{
		// new in 7.1: If I read the specs, this should use cal only if we don't
		// store the timezone, and if we do, then act just like getTime()?
		// for now...
		return getTime(i);
	}

	public Timestamp getTimestamp(int i, java.util.Calendar cal) throws SQLException
	{
		// new in 7.1: If I read the specs, this should use cal only if we don't
		// store the timezone, and if we do, then act just like getDate()?
		// for now...
		return getTimestamp(i);
	}

	public java.sql.Date getDate(String c, java.util.Calendar cal) throws SQLException
	{
		return getDate(findColumn(c), cal);
	}

	public Time getTime(String c, java.util.Calendar cal) throws SQLException
	{
		return getTime(findColumn(c), cal);
	}

	public Timestamp getTimestamp(String c, java.util.Calendar cal) throws SQLException
	{
		return getTimestamp(findColumn(c), cal);
	}

	public int getFetchDirection() throws SQLException
	{
		// new in 7.1: PostgreSQL normally sends rows first->last
		return FETCH_FORWARD;
	}

	public int getFetchSize() throws SQLException
	{
		// new in 7.1: In this implementation we return the entire result set, so
		// here return the number of rows we have. Sub-classes can return a proper
		// value
		return rows.size();
	}

	public Object getObject(String columnName, java.util.Map map) throws SQLException
	{
		return getObject(findColumn(columnName), map);
	}

	/**
	 * This checks against map for the type of column i, and if found returns
	 * an object based on that mapping. The class must implement the SQLData
	 * interface.
	 */
	public Object getObject(int i, java.util.Map map) throws SQLException
	{
		/* In preparation
		SQLInput s = new PSQLInput(this,i);
		String t = getTypeName(i);
		SQLData o = (SQLData) map.get(t);
		// If the type is not in the map, then pass to the existing code
		if(o==null)
		  return getObject(i);
		o.readSQL(s,t);
		return o;
		*/throw org.postgresql.Driver.notImplemented();
	}

	public Ref getRef(String columnName) throws SQLException
	{
		return getRef(findColumn(columnName));
	}

	public Ref getRef(int i) throws SQLException
	{
		// new in 7.1: The backend doesn't yet have SQL3 REF types
		throw new PSQLException("postgresql.psqlnotimp");
	}

	public int getRow() throws SQLException
	{
		return current_row + 1;
	}

	// This one needs some thought, as not all ResultSets come from a statement
	public java.sql.Statement getStatement() throws SQLException
	{
		return statement;
	}

	public int getType() throws SQLException
	{
		// New in 7.1. This implementation allows scrolling but is not able to
		// see any changes. Sub-classes may overide this to return a more
		// meaningful result.
		return TYPE_SCROLL_INSENSITIVE;
	}

	public void insertRow() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public boolean isAfterLast() throws SQLException
	{
		final int rows_size = rows.size();
		return (current_row >= rows_size && rows_size > 0);
	}

	public boolean isBeforeFirst() throws SQLException
	{
		return (current_row < 0 && rows.size() > 0);
	}

	public boolean isFirst() throws SQLException
	{
		return (current_row == 0 && rows.size() >= 0);
	}

	public boolean isLast() throws SQLException
	{
		final int rows_size = rows.size();
		return (current_row == rows_size - 1 && rows_size > 0);
	}

	public boolean last() throws SQLException
	{
		final int rows_size = rows.size();
		if (rows_size <= 0)
			return false;
		current_row = rows_size - 1;
		this_row = (byte [][])rows.elementAt(current_row);
		return true;
	}

	public void moveToCurrentRow() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void moveToInsertRow() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public boolean previous() throws SQLException
	{
		if (--current_row < 0)
			return false;
		this_row = (byte [][])rows.elementAt(current_row);
		return true;
	}

	public void refreshRow() throws SQLException
	{
		throw new PSQLException("postgresql.notsensitive");
	}

	// Peter: Implemented in 7.0
	public boolean relative(int rows) throws SQLException
	{
		//have to add 1 since absolute expects a 1-based index
		return absolute(current_row + 1 + rows);
	}

	public boolean rowDeleted() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
		return false; // javac complains about not returning a value!
	}

	public boolean rowInserted() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
		return false; // javac complains about not returning a value!
	}

	public boolean rowUpdated() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
		return false; // javac complains about not returning a value!
	}

	public void setFetchDirection(int direction) throws SQLException
	{
		// In 7.1, the backend doesn't yet support this
		throw new PSQLException("postgresql.psqlnotimp");
	}

	public void setFetchSize(int rows) throws SQLException
	{
		// Sub-classes should implement this as part of their cursor support
		throw org.postgresql.Driver.notImplemented();
	}

	public void updateAsciiStream(int columnIndex,
								  java.io.InputStream x,
								  int length
								 ) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateAsciiStream(String columnName,
								  java.io.InputStream x,
								  int length
								 ) throws SQLException
	{
		updateAsciiStream(findColumn(columnName), x, length);
	}

	public void updateBigDecimal(int columnIndex,
								 java.math.BigDecimal x
								) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateBigDecimal(String columnName,
								 java.math.BigDecimal x
								) throws SQLException
	{
		updateBigDecimal(findColumn(columnName), x);
	}

	public void updateBinaryStream(int columnIndex,
								   java.io.InputStream x,
								   int length
								  ) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateBinaryStream(String columnName,
								   java.io.InputStream x,
								   int length
								  ) throws SQLException
	{
		updateBinaryStream(findColumn(columnName), x, length);
	}

	public void updateBoolean(int columnIndex, boolean x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateBoolean(String columnName, boolean x) throws SQLException
	{
		updateBoolean(findColumn(columnName), x);
	}

	public void updateByte(int columnIndex, byte x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateByte(String columnName, byte x) throws SQLException
	{
		updateByte(findColumn(columnName), x);
	}

	public void updateBytes(String columnName, byte[] x) throws SQLException
	{
		updateBytes(findColumn(columnName), x);
	}

	public void updateBytes(int columnIndex, byte[] x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateCharacterStream(int columnIndex,
									  java.io.Reader x,
									  int length
									 ) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateCharacterStream(String columnName,
									  java.io.Reader x,
									  int length
									 ) throws SQLException
	{
		updateCharacterStream(findColumn(columnName), x, length);
	}

	public void updateDate(int columnIndex, java.sql.Date x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateDate(String columnName, java.sql.Date x) throws SQLException
	{
		updateDate(findColumn(columnName), x);
	}

	public void updateDouble(int columnIndex, double x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateDouble(String columnName, double x) throws SQLException
	{
		updateDouble(findColumn(columnName), x);
	}

	public void updateFloat(int columnIndex, float x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateFloat(String columnName, float x) throws SQLException
	{
		updateFloat(findColumn(columnName), x);
	}

	public void updateInt(int columnIndex, int x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateInt(String columnName, int x) throws SQLException
	{
		updateInt(findColumn(columnName), x);
	}

	public void updateLong(int columnIndex, long x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateLong(String columnName, long x) throws SQLException
	{
		updateLong(findColumn(columnName), x);
	}

	public void updateNull(int columnIndex) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateNull(String columnName) throws SQLException
	{
		updateNull(findColumn(columnName));
	}

	public void updateObject(int columnIndex, Object x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateObject(String columnName, Object x) throws SQLException
	{
		updateObject(findColumn(columnName), x);
	}

	public void updateObject(int columnIndex, Object x, int scale) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateObject(String columnName, Object x, int scale) throws SQLException
	{
		updateObject(findColumn(columnName), x, scale);
	}

	public void updateRow() throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateShort(int columnIndex, short x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateShort(String columnName, short x) throws SQLException
	{
		updateShort(findColumn(columnName), x);
	}

	public void updateString(int columnIndex, String x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateString(String columnName, String x) throws SQLException
	{
		updateString(findColumn(columnName), x);
	}

	public void updateTime(int columnIndex, Time x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateTime(String columnName, Time x) throws SQLException
	{
		updateTime(findColumn(columnName), x);
	}

	public void updateTimestamp(int columnIndex, Timestamp x) throws SQLException
	{
		// only sub-classes implement CONCUR_UPDATEABLE
		notUpdateable();
	}

	public void updateTimestamp(String columnName, Timestamp x) throws SQLException
	{
		updateTimestamp(findColumn(columnName), x);
	}

	// helper method. Throws an SQLException when an update is not possible
	public void notUpdateable() throws SQLException
	{
		throw new PSQLException("postgresql.noupdate");
	}

	/**
	 * This is called by Statement to register itself with this statement.
	 * It's used currently by getStatement() but may also with the new core
	 * package.
	 */
	public void setStatement(org.postgresql.jdbc2.Statement statement)
	{
		this.statement = statement;
	}

	//----------------- Formatting Methods -------------------

	public static boolean toBoolean(String s)
	{
		if (s != null)
		{
			int c = s.charAt(0);
			return ((c == 't') || (c == 'T') || (c == '1'));
		}
		return false;		// SQL NULL
	}

	public static int toInt(String s) throws SQLException
	{
		if (s != null)
		{
			try
			{
				return Integer.parseInt(s);
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException ("postgresql.res.badint", s);
			}
		}
		return 0;		// SQL NULL
	}

	public static long toLong(String s) throws SQLException
	{
		if (s != null)
		{
			try
			{
				return Long.parseLong(s);
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException ("postgresql.res.badlong", s);
			}
		}
		return 0;		// SQL NULL
	}

	public static BigDecimal toBigDecimal(String s, int scale) throws SQLException
	{
		BigDecimal val;
		if (s != null)
		{
			try
			{
				val = new BigDecimal(s);
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException ("postgresql.res.badbigdec", s);
			}
			if (scale == -1)
				return val;
			try
			{
				return val.setScale(scale);
			}
			catch (ArithmeticException e)
			{
				throw new PSQLException ("postgresql.res.badbigdec", s);
			}
		}
		return null;		// SQL NULL
	}

	public static float toFloat(String s) throws SQLException
	{
		if (s != null)
		{
			try
			{
				return Float.valueOf(s).floatValue();
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException ("postgresql.res.badfloat", s);
			}
		}
		return 0;		// SQL NULL
	}

	public static double toDouble(String s) throws SQLException
	{
		if (s != null)
		{
			try
			{
				return Double.valueOf(s).doubleValue();
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException ("postgresql.res.baddouble", s);
			}
		}
		return 0;		// SQL NULL
	}

	public static java.sql.Date toDate(String s) throws SQLException
	{
		if (s == null)
			return null;
		return java.sql.Date.valueOf(s);
	}

	public static Time toTime(String s) throws SQLException
	{
		if (s == null)
			return null; // SQL NULL
		return java.sql.Time.valueOf(s);
	}

	public static Timestamp toTimestamp(String s, ResultSet resultSet) throws SQLException
	{
		if (s == null)
			return null;

		boolean subsecond;
		//if string contains a '.' we have fractional seconds
		if (s.indexOf('.') == -1)
		{
			subsecond = false;
		}
		else
		{
			subsecond = true;
		}

		//here we are modifying the string from ISO format to a format java can understand
		//java expects timezone info as 'GMT-08:00' instead of '-08' in postgres ISO format
		//and java expects three digits if fractional seconds are present instead of two for postgres
		//so this code strips off timezone info and adds on the GMT+/-...
		//as well as adds a third digit for partial seconds if necessary
		synchronized (resultSet)
		{
			// We must be synchronized here incase more theads access the ResultSet
			// bad practice but possible. Anyhow this is to protect sbuf and
			// SimpleDateFormat objects

			// First time?
			if (resultSet.sbuf == null)
				resultSet.sbuf = new StringBuffer();

			resultSet.sbuf.setLength(0);
			resultSet.sbuf.append(s);

			char sub = resultSet.sbuf.charAt(resultSet.sbuf.length() - 3);
			if (sub == '+' || sub == '-')
			{
				resultSet.sbuf.setLength(resultSet.sbuf.length() - 3);
				if (subsecond)
				{
					resultSet.sbuf.append('0').append("GMT").append(s.substring(s.length() - 3)).append(":00");
				}
				else
				{
					resultSet.sbuf.append("GMT").append(s.substring(s.length() - 3)).append(":00");
				}
			}
			else if (subsecond)
			{
				resultSet.sbuf.append('0');
			}

			// could optimize this a tad to remove too many object creations...
			SimpleDateFormat df = null;

			if (resultSet.sbuf.length() > 23 && subsecond)
			{
				df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSzzzzzzzzz");
			}
			else if (resultSet.sbuf.length() > 23 && !subsecond)
			{
				df = new SimpleDateFormat("yyyy-MM-dd HH:mm:sszzzzzzzzz");
			}
			else if (resultSet.sbuf.length() > 10 && subsecond)
			{
				df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
			}
			else if (resultSet.sbuf.length() > 10 && !subsecond)
			{
				df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
			}
			else
			{
				df = new SimpleDateFormat("yyyy-MM-dd");
			}

			try
			{
				return new Timestamp(df.parse(resultSet.sbuf.toString()).getTime());
			}
			catch (ParseException e)
			{
				throw new PSQLException("postgresql.res.badtimestamp", new Integer(e.getErrorOffset()), s);
			}
		}
	}


}

