<?php /** * TDbDataReader class file * * @author Qiang Xue <qiang.xue@gmail.com> * @link http://www.pradosoft.com/ * @copyright Copyright © 2005-2008 PradoSoft * @license http://www.pradosoft.com/license/ * @version $Id$ * @package System.Data */ /** * TDbDataReader class. * * TDbDataReader represents a forward-only stream of rows from a query result set. * * To read the current row of data, call {@link read}. The method {@link readAll} * returns all the rows in a single array. * * One can also retrieve the rows of data in TDbDataReader by using foreach: * <code> * foreach($reader as $row) * // $row represents a row of data * </code> * Since TDbDataReader is a forward-only stream, you can only traverse it once. * * It is possible to use a specific mode of data fetching by setting * {@link setFetchMode FetchMode}. See {@link http://www.php.net/manual/en/function.PDOStatement-setFetchMode.php} * for more details. * * @author Qiang Xue <qiang.xue@gmail.com> * @version $Id$ * @package System.Data * @since 3.0 */ class TDbDataReader extends TComponent implements Iterator { private $_statement; private $_closed=false; private $_row; private $_index=-1; /** * Constructor. * @param TDbCommand the command generating the query result */ public function __construct(TDbCommand $command) { $this->_statement=$command->getPdoStatement(); $this->_statement->setFetchMode(PDO::FETCH_ASSOC); } /** * Binds a column to a PHP variable. * When rows of data are being fetched, the corresponding column value * will be set in the variable. Note, the fetch mode must include PDO::FETCH_BOUND. * @param mixed Number of the column (1-indexed) or name of the column * in the result set. If using the column name, be aware that the name * should match the case of the column, as returned by the driver. * @param mixed Name of the PHP variable to which the column will be bound. * @param int Data type of the parameter * @see http://www.php.net/manual/en/function.PDOStatement-bindColumn.php */ public function bindColumn($column, &$value, $dataType=null) { if($dataType===null) $this->_statement->bindColumn($column,$value); else $this->_statement->bindColumn($column,$value,$dataType); } /** * @see http://www.php.net/manual/en/function.PDOStatement-setFetchMode.php */ public function setFetchMode($mode) { $params=func_get_args(); call_user_func_array(array($this->_statement,'setFetchMode'),$params); } /** * Advances the reader to the next row in a result set. * @return array|false the current row, false if no more row available */ public function read() { return $this->_statement->fetch(); } /** * Returns a single column from the next row of a result set. * @param int zero-based column index * @return mixed|false the column of the current row, false if no more row available */ public function readColumn($columnIndex) { return $this->_statement->fetchColumn($columnIndex); } /** * Returns a single column from the next row of a result set. * @param string class name of the object to be created and populated * @param array list of column names whose values are to be passed as parameters in the constructor of the class being created * @return mixed|false the populated object, false if no more row of data available */ public function readObject($className,$fields) { return $this->_statement->fetchObject($className,$fields); } /** * Reads the whole result set into an array. * @return array the result set (each array element represents a row of data). * An empty array will be returned if the result contains no row. */ public function readAll() { return $this->_statement->fetchAll(); } /** * Advances the reader to the next result when reading the results of a batch of statements. * This method is only useful when there are multiple result sets * returned by the query. Not all DBMS support this feature. */ public function nextResult() { return $this->_statement->nextRowset(); } /** * Closes the reader. * Any further data reading will result in an exception. */ public function close() { $this->_statement->closeCursor(); $this->_closed=true; } /** * @return boolean whether the reader is closed or not. */ public function getIsClosed() { return $this->_closed; } /** * @return int number of rows contained in the result. * Note, most DBMS may not give a meaningful count. * In this case, use "SELECT COUNT(*) FROM tableName" to obtain the number of rows. */ public function getRowCount() { return $this->_statement->rowCount(); } /** * @return int the number of columns in the result set. * Note, even there's no row in the reader, this still gives correct column number. */ public function getColumnCount() { return $this->_statement->columnCount(); } /** * Resets the iterator to the initial state. * This method is required by the interface Iterator. * @throws TDbException if this method is invoked twice */ public function rewind() { if($this->_index<0) { $this->_row=$this->_statement->fetch(); $this->_index=0; } else throw new TDbException('dbdatareader_rewind_invalid'); } /** * Returns the index of the current row. * This method is required by the interface Iterator. * @return integer the index of the current row. */ public function key() { return $this->_index; } /** * Returns the current row. * This method is required by the interface Iterator. * @return mixed the current row. */ public function current() { return $this->_row; } /** * Moves the internal pointer to the next row. * This method is required by the interface Iterator. */ public function next() { $this->_row=$this->_statement->fetch(); $this->_index++; } /** * Returns whether there is a row of data at current position. * This method is required by the interface Iterator. * @return boolean whether there is a row of data at current position. */ public function valid() { return $this->_row!==false; } }