package org.postgresql.jdbc1;

// IMPORTANT NOTE: This file implements the JDBC 1 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 2 class in the
// org.postgresql.jdbc2 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
{
	/*
	 * 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, long 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)
		rows.setSize(0);
	}

	/*
	 * 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
	{
		checkResultSet( columnIndex );
		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
	{
		String s = getString(columnIndex);

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

	/*
	 * 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
	{
		String s = getFixedString(columnIndex);

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

	/*
	 * 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
	{
		String s = getFixedString(columnIndex);

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

	/*
	 * 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
	{
		String s = getFixedString(columnIndex);

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

	/*
	 * 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
	{
		String s = getFixedString(columnIndex);

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

	/*
	 * 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
	 */
	public BigDecimal getBigDecimal(int columnIndex, int scale) throws SQLException
	{
		String s = getFixedString(columnIndex);
		BigDecimal val;

		if (s != null)
		{
			try
			{
				val = new BigDecimal(s);
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException ("postgresql.res.badbigdec", s);
			}
			try
			{
				return val.setScale(scale);
			}
			catch (ArithmeticException e)
			{
				throw new PSQLException ("postgresql.res.badbigdec", s);
			}
		}
		return null;		// SQL NULL
	}

	/*
	 * 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
	{
		checkResultSet( columnIndex );
		wasNullFlag = (this_row[columnIndex - 1] == null);
		if (!wasNullFlag)
		{
			if (binaryCursor)
			{
				//If the data is already binary then just return it
				return this_row[columnIndex - 1];
			}
			else if (connection.haveMinimumCompatibleVersion("7.2"))
			{
				//Version 7.2 supports the bytea datatype for byte arrays
				if (fields[columnIndex - 1].getPGType().equals("bytea"))
				{
					return PGbytea.toBytes(this_row[columnIndex - 1]);
				}
				else
				{
					return this_row[columnIndex - 1];
				}
			}
			else
			{
				//Version 7.1 and earlier supports LargeObjects for byte arrays
				// Handle OID's as BLOBS
				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;
				}
				else
				{
					return this_row[columnIndex - 1];
				}
			}
		}
		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
	{
		String s = getString(columnIndex);
		if (s == null)
			return null;
		// length == 10: SQL Date
		// length >  10: SQL Timestamp, assumes PGDATESTYLE=ISO
		try
		{
			return java.sql.Date.valueOf((s.length() == 10) ? s : s.substring(0, 10));
		}
		catch (NumberFormatException e)
		{
			throw new PSQLException("postgresql.res.baddate", s);
		}
	}

	/*
	 * 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
	{
		String s = getString(columnIndex);

		if (s != null)
		{
			try
			{
				if (s.length() != 5 && s.length() != 8)
					throw new NumberFormatException("Wrong Length!");
				int hr = Integer.parseInt(s.substring(0, 2));
				int min = Integer.parseInt(s.substring(3, 5));
				int sec = (s.length() == 5) ? 0 : Integer.parseInt(s.substring(6));
				return new Time(hr, min, sec);
			}
			catch (NumberFormatException e)
			{
				throw new PSQLException ("postgresql.res.badtime", s);
			}
		}
		return null;		// SQL NULL
	}

	/*
	 * Get the value of a column in the current row as a
	 * java.sql.Timestamp object
	 *
	 * The driver is set to return ISO date formated strings. We modify this 
    * string from the ISO format to a format that Java can understand. Java
    * expects timezone info as 'GMT+09:00' where as ISO gives '+09'.
    * Java also expects fractional seconds to 3 places where postgres
    * will give, none, 2 or 6 depending on the time and postgres version.
    * From version 7.2 postgres returns fractional seconds to 6 places.
    * If available, we drop the last 3 digits.
	 *
	 * @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
	{
		String s = getString(columnIndex);

		if (s == null)
			return null;

		StringBuffer sbuf = new StringBuffer(s);
		SimpleDateFormat df = null;

		int slen = s.length();

		if (slen > 19)
		{
			// The len of the ISO string to the second value is 19 chars. If
			// greater then 19, there should be tz info and perhaps fractional
			// second info which we need to change to java to read it.

			// cut the copy to second value "2001-12-07 16:29:22"
			int i = 19;
			sbuf.setLength(i);

			char c = s.charAt(i++);
			if (c == '.')
			{
				// Found a fractional value. Append up to 3 digits including
				// the leading '.'
				do
				{
					if (i < 24)
						sbuf.append(c);
					c = s.charAt(i++);
				} while (i < slen && Character.isDigit(c));

				// If there wasn't at least 3 digits we should add some zeros
				// to make up the 3 digits we tell java to expect.
				for (int j = i; j < 24; j++)
					sbuf.append('0');
			}
			else
			{
				// No fractional seconds, lets add some.
				sbuf.append(".000");
			}

			if (i < slen)
			{
				// prepend the GMT part and then add the remaining bit of
				// the string.
				sbuf.append(" GMT");
				sbuf.append(c);
				sbuf.append(s.substring(i, slen));

				// Lastly, if the tz part doesn't specify the :MM part then
				// we add ":00" for java.
				if (slen - i < 5)
					sbuf.append(":00");

				// we'll use this dateformat string to parse the result.
				df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS z");
			}
			else
			{
				df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
			}
		}
		else if (slen == 19)
		{
			// No tz or fractional second info. 
			// I'm not sure if it is
			// possible to have a string in this format, as pg
			// should give us tz qualified timestamps back, but it was
			// in the old code, so I'm handling it for now.
			df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		}
		else
		{
			// We must just have a date. This case is
			// needed if this method is called on a date column
			df = new SimpleDateFormat("yyyy-MM-dd");
		}

		try
		{
			// All that's left is to parse the string and return the ts.
			return new Timestamp(df.parse(sbuf.toString()).getTime());
		}
		catch (ParseException e)
		{
			throw new PSQLException("postgresql.res.badtimestamp", new Integer(e.getErrorOffset()), s);
		}
	}

	/*
	 * 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
	{
		checkResultSet( columnIndex );
		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.
	 *
	 * @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
	 */
	public InputStream getUnicodeStream(int columnIndex) throws SQLException
	{
		checkResultSet( columnIndex );
		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
	{
		checkResultSet( columnIndex );
		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));
	}

	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));
	}

	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");
		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() - 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;

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

