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Diffstat (limited to 'lib/prado/framework/Data/TDbDataReader.php')
| -rw-r--r-- | lib/prado/framework/Data/TDbDataReader.php | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/lib/prado/framework/Data/TDbDataReader.php b/lib/prado/framework/Data/TDbDataReader.php new file mode 100644 index 0000000..a74952e --- /dev/null +++ b/lib/prado/framework/Data/TDbDataReader.php @@ -0,0 +1,223 @@ +<?php +/** + * TDbDataReader class file + * + * @author Qiang Xue <qiang.xue@gmail.com> + * @link https://github.com/pradosoft/prado + * @copyright Copyright © 2005-2015 The PRADO Group + * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT + * @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> + * @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; + } +} + |