public static List<TableColumnDesc> getColumns(String sql) throws SQLException{
		List<TableColumnDesc> result = new ArrayList<TableColumnDesc>();
		Statement stt = con.createStatement();
		ResultSet rs =  stt.executeQuery(sql);
		while (rs.next()) {
			TableColumnDesc tcd = new TableColumnDesc();
			tcd.setField(rs.getString("FIELD"));
			tcd.setType(rs.getString("TYPE"));
			tcd.setIsKey(rs.getString("KEY"));
			tcd.setIsNull(rs.getString("NULL"));
			tcd.setExtra(rs.getString("EXTRA"));
			tcd.setDefault_(rs.getString("DEFAULT"));
			result.add(tcd);
		}
		return result;
	}