system/database/drivers/oci8/oci8_driver.php - code-igniter-v3-giggi - Gitiles

 <?php
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP
  *
  * This content is released under the MIT License (MIT)
  *
  * Copyright (c) 2014 - 2018, British Columbia Institute of Technology
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  *
  * @package	CodeIgniter
  * @author	EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
  * @copyright	Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
  * @license	http://opensource.org/licenses/MIT	MIT License
  * @link	https://codeigniter.com
  * @since	Version 1.4.1
  * @filesource
  */
 defined('BASEPATH') OR exit('No direct script access allowed');

 /**
  * oci8 Database Adapter Class
  *
  * Note: _DB is an extender class that the app controller
  * creates dynamically based on whether the query builder
  * class is being used or not.
  *
  * @package		CodeIgniter
  * @subpackage  Drivers
  * @category	Database
  * @author		EllisLab Dev Team
  * @link		https://codeigniter.com/user_guide/database/
  */

 /**
  * oci8 Database Adapter Class
  *
  * This is a modification of the DB_driver class to
  * permit access to oracle databases
  *
  * @author	  Kelly McArdle
  */
 class CI_DB_oci8_driver extends CI_DB {

 	/**
 	 * Database driver
 	 *
 	 * @var	string
 	 */
 	public $dbdriver = 'oci8';

 	/**
 	 * Statement ID
 	 *
 	 * @var	resource
 	 */
 	public $stmt_id;

 	/**
 	 * Cursor ID
 	 *
 	 * @var	resource
 	 */
 	public $curs_id;

 	/**
 	 * Commit mode flag
 	 *
 	 * @var	int
 	 */
 	public $commit_mode = OCI_COMMIT_ON_SUCCESS;

 	/**
 	 * Limit used flag
 	 *
 	 * If we use LIMIT, we'll add a field that will
 	 * throw off num_fields later.
 	 *
 	 * @var	bool
 	 */
 	public $limit_used = FALSE;

 	// --------------------------------------------------------------------

 	/**
 	 * Reset $stmt_id flag
 	 *
 	 * Used by stored_procedure() to prevent _execute() from
 	 * re-setting the statement ID.
 	 */
 	protected $_reset_stmt_id = TRUE;

 	/**
 	 * List of reserved identifiers
 	 *
 	 * Identifiers that must NOT be escaped.
 	 *
 	 * @var	string[]
 	 */
 	protected $_reserved_identifiers = array('*', 'rownum');

 	/**
 	 * ORDER BY random keyword
 	 *
 	 * @var	array
 	 */
 	protected $_random_keyword = array('ASC', 'ASC'); // not currently supported

 	/**
 	 * COUNT string
 	 *
 	 * @used-by	CI_DB_driver::count_all()
 	 * @used-by	CI_DB_query_builder::count_all_results()
 	 *
 	 * @var	string
 	 */
 	protected $_count_string = 'SELECT COUNT(1) AS ';

 	// --------------------------------------------------------------------

 	/**
 	 * Class constructor
 	 *
 	 * @param	array	$params
 	 * @return	void
 	 */
 	public function __construct($params)
 	{
 		parent::__construct($params);

 		$valid_dsns = array(
 			'tns'	=> '/^\(DESCRIPTION=(\(.+\)){2,}\)$/', // TNS
 			// Easy Connect string (Oracle 10g+)
 			'ec'	=> '/^(\/\/)?[a-z0-9.:_-]+(:[1-9][0-9]{0,4})?(\/[a-z0-9$_]+)?(:[^\/])?(\/[a-z0-9$_]+)?$/i',
 			'in'	=> '/^[a-z0-9$_]+$/i' // Instance name (defined in tnsnames.ora)
 		);

 		/* Space characters don't have any effect when actually
 		 * connecting, but can be a hassle while validating the DSN.
 		 */
 		$this->dsn = str_replace(array("\n", "\r", "\t", ' '), '', $this->dsn);

 		if ($this->dsn !== '')
 		{
 			foreach ($valid_dsns as $regexp)
 			{
 				if (preg_match($regexp, $this->dsn))
 				{
 					return;
 				}
 			}
 		}

 		// Legacy support for TNS in the hostname configuration field
 		$this->hostname = str_replace(array("\n", "\r", "\t", ' '), '', $this->hostname);
 		if (preg_match($valid_dsns['tns'], $this->hostname))
 		{
 			$this->dsn = $this->hostname;
 			return;
 		}
 		elseif ($this->hostname !== '' && strpos($this->hostname, '/') === FALSE && strpos($this->hostname, ':') === FALSE
 			&& (( ! empty($this->port) && ctype_digit($this->port)) OR $this->database !== ''))
 		{
 			/* If the hostname field isn't empty, doesn't contain
 			 * ':' and/or '/' and if port and/or database aren't
 			 * empty, then the hostname field is most likely indeed
 			 * just a hostname. Therefore we'll try and build an
 			 * Easy Connect string from these 3 settings, assuming
 			 * that the database field is a service name.
 			 */
 			$this->dsn = $this->hostname
 				.(( ! empty($this->port) && ctype_digit($this->port)) ? ':'.$this->port : '')
 				.($this->database !== '' ? '/'.ltrim($this->database, '/') : '');

 			if (preg_match($valid_dsns['ec'], $this->dsn))
 			{
 				return;
 			}
 		}

 		/* At this point, we can only try and validate the hostname and
 		 * database fields separately as DSNs.
 		 */
 		if (preg_match($valid_dsns['ec'], $this->hostname) OR preg_match($valid_dsns['in'], $this->hostname))
 		{
 			$this->dsn = $this->hostname;
 			return;
 		}

 		$this->database = str_replace(array("\n", "\r", "\t", ' '), '', $this->database);
 		foreach ($valid_dsns as $regexp)
 		{
 			if (preg_match($regexp, $this->database))
 			{
 				return;
 			}
 		}

 		/* Well - OK, an empty string should work as well.
 		 * PHP will try to use environment variables to
 		 * determine which Oracle instance to connect to.
 		 */
 		$this->dsn = '';
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Non-persistent database connection
 	 *
 	 * @param	bool	$persistent
 	 * @return	resource
 	 */
 	public function db_connect($persistent = FALSE)
 	{
 		$func = ($persistent === TRUE) ? 'oci_pconnect' : 'oci_connect';
 		return empty($this->char_set)
 			? $func($this->username, $this->password, $this->dsn)
 			: $func($this->username, $this->password, $this->dsn, $this->char_set);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Database version number
 	 *
 	 * @return	string
 	 */
 	public function version()
 	{
 		if (isset($this->data_cache['version']))
 		{
 			return $this->data_cache['version'];
 		}

 		if ( ! $this->conn_id OR ($version_string = oci_server_version($this->conn_id)) === FALSE)
 		{
 			return FALSE;
 		}
 		elseif (preg_match('#Release\s(\d+(?:\.\d+)+)#', $version_string, $match))
 		{
 			return $this->data_cache['version'] = $match[1];
 		}

 		return FALSE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Execute the query
 	 *
 	 * @param	string	$sql	an SQL query
 	 * @return	resource
 	 */
 	protected function _execute($sql)
 	{
 		/* Oracle must parse the query before it is run. All of the actions with
 		 * the query are based on the statement id returned by oci_parse().
 		 */
 		if ($this->_reset_stmt_id === TRUE)
 		{
 			$this->stmt_id = oci_parse($this->conn_id, $sql);
 		}

 		oci_set_prefetch($this->stmt_id, 1000);
 		return oci_execute($this->stmt_id, $this->commit_mode);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Get cursor. Returns a cursor from the database
 	 *
 	 * @return	resource
 	 */
 	public function get_cursor()
 	{
 		return $this->curs_id = oci_new_cursor($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Stored Procedure.  Executes a stored procedure
 	 *
 	 * @param	string	package name in which the stored procedure is in
 	 * @param	string	stored procedure name to execute
 	 * @param	array	parameters
 	 * @return	mixed
 	 *
 	 * params array keys
 	 *
 	 * KEY      OPTIONAL  NOTES
 	 * name     no        the name of the parameter should be in :<param_name> format
 	 * value    no        the value of the parameter.  If this is an OUT or IN OUT parameter,
 	 *                    this should be a reference to a variable
 	 * type     yes       the type of the parameter
 	 * length   yes       the max size of the parameter
 	 */
 	public function stored_procedure($package, $procedure, array $params)
 	{
 		if ($package === '' OR $procedure === '')
 		{
 			log_message('error', 'Invalid query: '.$package.'.'.$procedure);
 			return ($this->db_debug) ? $this->display_error('db_invalid_query') : FALSE;
 		}

 		// Build the query string
 		$sql = 'BEGIN '.$package.'.'.$procedure.'(';

 		$have_cursor = FALSE;
 		foreach ($params as $param)
 		{
 			$sql .= $param['name'].',';

 			if (isset($param['type']) && $param['type'] === OCI_B_CURSOR)
 			{
 				$have_cursor = TRUE;
 			}
 		}
 		$sql = trim($sql, ',').'); END;';

 		$this->_reset_stmt_id = FALSE;
 		$this->stmt_id = oci_parse($this->conn_id, $sql);
 		$this->_bind_params($params);
 		$result = $this->query($sql, FALSE, $have_cursor);
 		$this->_reset_stmt_id = TRUE;
 		return $result;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Bind parameters
 	 *
 	 * @param	array	$params
 	 * @return	void
 	 */
 	protected function _bind_params($params)
 	{
 		if ( ! is_array($params) OR ! is_resource($this->stmt_id))
 		{
 			return;
 		}

 		foreach ($params as $param)
 		{
 			foreach (array('name', 'value', 'type', 'length') as $val)
 			{
 				if ( ! isset($param[$val]))
 				{
 					$param[$val] = '';
 				}
 			}

 			oci_bind_by_name($this->stmt_id, $param['name'], $param['value'], $param['length'], $param['type']);
 		}
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Begin Transaction
 	 *
 	 * @return	bool
 	 */
 	protected function _trans_begin()
 	{
 		$this->commit_mode = OCI_NO_AUTO_COMMIT;
 		return TRUE;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Commit Transaction
 	 *
 	 * @return	bool
 	 */
 	protected function _trans_commit()
 	{
 		$this->commit_mode = OCI_COMMIT_ON_SUCCESS;

 		return oci_commit($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Rollback Transaction
 	 *
 	 * @return	bool
 	 */
 	protected function _trans_rollback()
 	{
 		$this->commit_mode = OCI_COMMIT_ON_SUCCESS;
 		return oci_rollback($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Affected Rows
 	 *
 	 * @return	int
 	 */
 	public function affected_rows()
 	{
 		return oci_num_rows($this->stmt_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Insert ID
 	 *
 	 * @return	int
 	 */
 	public function insert_id()
 	{
 		// not supported in oracle
 		return $this->display_error('db_unsupported_function');
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Show table query
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
 	 * @param	bool	$prefix_limit
 	 * @return	string
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
 		$sql = 'SELECT "TABLE_NAME" FROM "ALL_TABLES"';

 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
 			return $sql.' WHERE "TABLE_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' "
 				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}

 		return $sql;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Show column query
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
 	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _list_columns($table = '')
 	{
 		if (strpos($table, '.') !== FALSE)
 		{
 			sscanf($table, '%[^.].%s', $owner, $table);
 		}
 		else
 		{
 			$owner = $this->username;
 		}

 		return 'SELECT COLUMN_NAME FROM ALL_TAB_COLUMNS
 			WHERE UPPER(OWNER) = '.$this->escape(strtoupper($owner)).'
 				AND UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Returns an object with field data
 	 *
 	 * @param	string	$table
 	 * @return	array
 	 */
 	public function field_data($table)
 	{
 		if (strpos($table, '.') !== FALSE)
 		{
 			sscanf($table, '%[^.].%s', $owner, $table);
 		}
 		else
 		{
 			$owner = $this->username;
 		}

 		$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHAR_LENGTH, DATA_PRECISION, DATA_LENGTH, DATA_DEFAULT, NULLABLE
 			FROM ALL_TAB_COLUMNS
 			WHERE UPPER(OWNER) = '.$this->escape(strtoupper($owner)).'
 				AND UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));

 		if (($query = $this->query($sql)) === FALSE)
 		{
 			return FALSE;
 		}
 		$query = $query->result_object();

 		$retval = array();
 		for ($i = 0, $c = count($query); $i < $c; $i++)
 		{
 			$retval[$i]			= new stdClass();
 			$retval[$i]->name		= $query[$i]->COLUMN_NAME;
 			$retval[$i]->type		= $query[$i]->DATA_TYPE;

 			$length = ($query[$i]->CHAR_LENGTH > 0)
 				? $query[$i]->CHAR_LENGTH : $query[$i]->DATA_PRECISION;
 			if ($length === NULL)
 			{
 				$length = $query[$i]->DATA_LENGTH;
 			}
 			$retval[$i]->max_length		= $length;

 			$default = $query[$i]->DATA_DEFAULT;
 			if ($default === NULL && $query[$i]->NULLABLE === 'N')
 			{
 				$default = '';
 			}
 			$retval[$i]->default = $default;
 		}

 		return $retval;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
 	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
 	public function error()
 	{
 		// oci_error() returns an array that already contains
 		// 'code' and 'message' keys, but it can return false
 		// if there was no error ....
 		if (is_resource($this->curs_id))
 		{
 			$error = oci_error($this->curs_id);
 		}
 		elseif (is_resource($this->stmt_id))
 		{
 			$error = oci_error($this->stmt_id);
 		}
 		elseif (is_resource($this->conn_id))
 		{
 			$error = oci_error($this->conn_id);
 		}
 		else
 		{
 			$error = oci_error();
 		}

 		return is_array($error)
 			? $error
 			: array('code' => '', 'message' => '');
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Insert batch statement
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
 	 * @param	string	$table	Table name
 	 * @param	array	$keys	INSERT keys
 	 * @param 	array	$values	INSERT values
 	 * @return	string
 	 */
 	protected function _insert_batch($table, $keys, $values)
 	{
 		$keys = implode(', ', $keys);
 		$sql = "INSERT ALL\n";

 		for ($i = 0, $c = count($values); $i < $c; $i++)
 		{
 			$sql .= '	INTO '.$table.' ('.$keys.') VALUES '.$values[$i]."\n";
 		}

 		return $sql.'SELECT * FROM dual';
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
 	 *
 	 * If the database does not support the TRUNCATE statement,
 	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
 		return 'TRUNCATE TABLE '.$table;
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Delete statement
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
 	 * @param	string	$table
 	 * @return	string
 	 */
 	protected function _delete($table)
 	{
 		if ($this->qb_limit)
 		{
 			$this->where('rownum <= ',$this->qb_limit, FALSE);
 			$this->qb_limit = FALSE;
 		}

 		return parent::_delete($table);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * LIMIT
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	$sql	SQL Query
 	 * @return	string
 	 */
 	protected function _limit($sql)
 	{
 		if (version_compare($this->version(), '12.1', '>='))
 		{
 			// OFFSET-FETCH can be used only with the ORDER BY clause
 			empty($this->qb_orderby) && $sql .= ' ORDER BY 1';

 			return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
 		}

 		$this->limit_used = TRUE;
 		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
 			.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1) : '');
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
 	 */
 	protected function _close()
 	{
 		oci_close($this->conn_id);
 	}

 	// --------------------------------------------------------------------

 	/**
 	 * We need to reset our $limit_used hack flag, so it doesn't propagate
 	 * to subsequent queries.
 	 *
 	 * @return	void
 	 */
 	protected function _reset_select()
 	{
 		$this->limit_used = FALSE;
 		parent::_reset_select();
 	}
 }
	<?php
	/**
	* CodeIgniter
	*
	* An open source application development framework for PHP
	*
	* This content is released under the MIT License (MIT)
	*
	* Copyright (c) 2014 - 2018, British Columbia Institute of Technology
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*
	* @package CodeIgniter
	* @author EllisLab Dev Team
	* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
	* @copyright Copyright (c) 2014 - 2018, British Columbia Institute of Technology (http://bcit.ca/)
	* @license http://opensource.org/licenses/MIT MIT License
	* @link https://codeigniter.com
	* @since Version 1.4.1
	* @filesource
	*/
	defined('BASEPATH') OR exit('No direct script access allowed');

	/**
	* oci8 Database Adapter Class
	*
	* Note: _DB is an extender class that the app controller
	* creates dynamically based on whether the query builder
	* class is being used or not.
	*
	* @package CodeIgniter
	* @subpackage Drivers
	* @category Database
	* @author EllisLab Dev Team
	* @link https://codeigniter.com/user_guide/database/
	*/

	/**
	* oci8 Database Adapter Class
	*
	* This is a modification of the DB_driver class to
	* permit access to oracle databases
	*
	* @author Kelly McArdle
	*/
	class CI_DB_oci8_driver extends CI_DB {

	/**
	* Database driver
	*
	* @var string
	*/
	public $dbdriver = 'oci8';

	/**
	* Statement ID
	*
	* @var resource
	*/
	public $stmt_id;

	/**
	* Cursor ID
	*
	* @var resource
	*/
	public $curs_id;

	/**
	* Commit mode flag
	*
	* @var int
	*/
	public $commit_mode = OCI_COMMIT_ON_SUCCESS;

	/**
	* Limit used flag
	*
	* If we use LIMIT, we'll add a field that will
	* throw off num_fields later.
	*
	* @var bool
	*/
	public $limit_used = FALSE;

	// --------------------------------------------------------------------

	/**
	* Reset $stmt_id flag
	*
	* Used by stored_procedure() to prevent _execute() from
	* re-setting the statement ID.
	*/
	protected $_reset_stmt_id = TRUE;

	/**
	* List of reserved identifiers
	*
	* Identifiers that must NOT be escaped.
	*
	* @var string[]
	*/
	protected $_reserved_identifiers = array('*', 'rownum');

	/**
	* ORDER BY random keyword
	*
	* @var array
	*/
	protected $_random_keyword = array('ASC', 'ASC'); // not currently supported

	/**
	* COUNT string
	*
	* @used-by CI_DB_driver::count_all()
	* @used-by CI_DB_query_builder::count_all_results()
	*
	* @var string
	*/
	protected $_count_string = 'SELECT COUNT(1) AS ';

	// --------------------------------------------------------------------

	/**
	* Class constructor
	*
	* @param array $params
	* @return void
	*/
	public function __construct($params)
	{
	parent::__construct($params);

	$valid_dsns = array(
	'tns' => '/^\(DESCRIPTION=(\(.+\)){2,}\)$/', // TNS
	// Easy Connect string (Oracle 10g+)
	'ec' => '/^(\/\/)?[a-z0-9.:_-]+(:[1-9][0-9]{0,4})?(\/[a-z0-9$_]+)?(:[^\/])?(\/[a-z0-9$_]+)?$/i',
	'in' => '/^[a-z0-9$_]+$/i' // Instance name (defined in tnsnames.ora)
	);

	/* Space characters don't have any effect when actually
	* connecting, but can be a hassle while validating the DSN.
	*/
	$this->dsn = str_replace(array("\n", "\r", "\t", ' '), '', $this->dsn);

	if ($this->dsn !== '')
	{
	foreach ($valid_dsns as $regexp)
	{
	if (preg_match($regexp, $this->dsn))
	{
	return;
	}
	}
	}

	// Legacy support for TNS in the hostname configuration field
	$this->hostname = str_replace(array("\n", "\r", "\t", ' '), '', $this->hostname);
	if (preg_match($valid_dsns['tns'], $this->hostname))
	{
	$this->dsn = $this->hostname;
	return;
	}
	elseif ($this->hostname !== '' && strpos($this->hostname, '/') === FALSE && strpos($this->hostname, ':') === FALSE
	&& (( ! empty($this->port) && ctype_digit($this->port)) OR $this->database !== ''))
	{
	/* If the hostname field isn't empty, doesn't contain
	* ':' and/or '/' and if port and/or database aren't
	* empty, then the hostname field is most likely indeed
	* just a hostname. Therefore we'll try and build an
	* Easy Connect string from these 3 settings, assuming
	* that the database field is a service name.
	*/
	$this->dsn = $this->hostname
	.(( ! empty($this->port) && ctype_digit($this->port)) ? ':'.$this->port : '')
	.($this->database !== '' ? '/'.ltrim($this->database, '/') : '');

	if (preg_match($valid_dsns['ec'], $this->dsn))
	{
	return;
	}
	}

	/* At this point, we can only try and validate the hostname and
	* database fields separately as DSNs.
	*/
	if (preg_match($valid_dsns['ec'], $this->hostname) OR preg_match($valid_dsns['in'], $this->hostname))
	{
	$this->dsn = $this->hostname;
	return;
	}

	$this->database = str_replace(array("\n", "\r", "\t", ' '), '', $this->database);
	foreach ($valid_dsns as $regexp)
	{
	if (preg_match($regexp, $this->database))
	{
	return;
	}
	}

	/* Well - OK, an empty string should work as well.
	* PHP will try to use environment variables to
	* determine which Oracle instance to connect to.
	*/
	$this->dsn = '';
	}

	// --------------------------------------------------------------------

	/**
	* Non-persistent database connection
	*
	* @param bool $persistent
	* @return resource
	*/
	public function db_connect($persistent = FALSE)
	{
	$func = ($persistent === TRUE) ? 'oci_pconnect' : 'oci_connect';
	return empty($this->char_set)
	? $func($this->username, $this->password, $this->dsn)
	: $func($this->username, $this->password, $this->dsn, $this->char_set);
	}

	// --------------------------------------------------------------------

	/**
	* Database version number
	*
	* @return string
	*/
	public function version()
	{
	if (isset($this->data_cache['version']))
	{
	return $this->data_cache['version'];
	}

	if ( ! $this->conn_id OR ($version_string = oci_server_version($this->conn_id)) === FALSE)
	{
	return FALSE;
	}
	elseif (preg_match('#Release\s(\d+(?:\.\d+)+)#', $version_string, $match))
	{
	return $this->data_cache['version'] = $match[1];
	}

	return FALSE;
	}

	// --------------------------------------------------------------------

	/**
	* Execute the query
	*
	* @param string $sql an SQL query
	* @return resource
	*/
	protected function _execute($sql)
	{
	/* Oracle must parse the query before it is run. All of the actions with
	* the query are based on the statement id returned by oci_parse().
	*/
	if ($this->_reset_stmt_id === TRUE)
	{
	$this->stmt_id = oci_parse($this->conn_id, $sql);
	}

	oci_set_prefetch($this->stmt_id, 1000);
	return oci_execute($this->stmt_id, $this->commit_mode);
	}

	// --------------------------------------------------------------------

	/**
	* Get cursor. Returns a cursor from the database
	*
	* @return resource
	*/
	public function get_cursor()
	{
	return $this->curs_id = oci_new_cursor($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Stored Procedure. Executes a stored procedure
	*
	* @param string package name in which the stored procedure is in
	* @param string stored procedure name to execute
	* @param array parameters
	* @return mixed
	*
	* params array keys
	*
	* KEY OPTIONAL NOTES
	* name no the name of the parameter should be in :<param_name> format
	* value no the value of the parameter. If this is an OUT or IN OUT parameter,
	* this should be a reference to a variable
	* type yes the type of the parameter
	* length yes the max size of the parameter
	*/
	public function stored_procedure($package, $procedure, array $params)
	{
	if ($package === '' OR $procedure === '')
	{
	log_message('error', 'Invalid query: '.$package.'.'.$procedure);
	return ($this->db_debug) ? $this->display_error('db_invalid_query') : FALSE;
	}

	// Build the query string
	$sql = 'BEGIN '.$package.'.'.$procedure.'(';

	$have_cursor = FALSE;
	foreach ($params as $param)
	{
	$sql .= $param['name'].',';

	if (isset($param['type']) && $param['type'] === OCI_B_CURSOR)
	{
	$have_cursor = TRUE;
	}
	}
	$sql = trim($sql, ',').'); END;';

	$this->_reset_stmt_id = FALSE;
	$this->stmt_id = oci_parse($this->conn_id, $sql);
	$this->_bind_params($params);
	$result = $this->query($sql, FALSE, $have_cursor);
	$this->_reset_stmt_id = TRUE;
	return $result;
	}

	// --------------------------------------------------------------------

	/**
	* Bind parameters
	*
	* @param array $params
	* @return void
	*/
	protected function _bind_params($params)
	{
	if ( ! is_array($params) OR ! is_resource($this->stmt_id))
	{
	return;
	}

	foreach ($params as $param)
	{
	foreach (array('name', 'value', 'type', 'length') as $val)
	{
	if ( ! isset($param[$val]))
	{
	$param[$val] = '';
	}
	}

	oci_bind_by_name($this->stmt_id, $param['name'], $param['value'], $param['length'], $param['type']);
	}
	}

	// --------------------------------------------------------------------

	/**
	* Begin Transaction
	*
	* @return bool
	*/
	protected function _trans_begin()
	{
	$this->commit_mode = OCI_NO_AUTO_COMMIT;
	return TRUE;
	}

	// --------------------------------------------------------------------

	/**
	* Commit Transaction
	*
	* @return bool
	*/
	protected function _trans_commit()
	{
	$this->commit_mode = OCI_COMMIT_ON_SUCCESS;

	return oci_commit($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Rollback Transaction
	*
	* @return bool
	*/
	protected function _trans_rollback()
	{
	$this->commit_mode = OCI_COMMIT_ON_SUCCESS;
	return oci_rollback($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* Affected Rows
	*
	* @return int
	*/
	public function affected_rows()
	{
	return oci_num_rows($this->stmt_id);
	}

	// --------------------------------------------------------------------

	/**
	* Insert ID
	*
	* @return int
	*/
	public function insert_id()
	{
	// not supported in oracle
	return $this->display_error('db_unsupported_function');
	}

	// --------------------------------------------------------------------

	/**
	* Show table query
	*
	* Generates a platform-specific query string so that the table names can be fetched
	*
	* @param bool $prefix_limit
	* @return string
	*/
	protected function _list_tables($prefix_limit = FALSE)
	{
	$sql = 'SELECT "TABLE_NAME" FROM "ALL_TABLES"';

	if ($prefix_limit !== FALSE && $this->dbprefix !== '')
	{
	return $sql.' WHERE "TABLE_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' "
	.sprintf($this->_like_escape_str, $this->_like_escape_chr);
	}

	return $sql;
	}

	// --------------------------------------------------------------------

	/**
	* Show column query
	*
	* Generates a platform-specific query string so that the column names can be fetched
	*
	* @param string $table
	* @return string
	*/
	protected function _list_columns($table = '')
	{
	if (strpos($table, '.') !== FALSE)
	{
	sscanf($table, '%[^.].%s', $owner, $table);
	}
	else
	{
	$owner = $this->username;
	}

	return 'SELECT COLUMN_NAME FROM ALL_TAB_COLUMNS
	WHERE UPPER(OWNER) = '.$this->escape(strtoupper($owner)).'
	AND UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
	}

	// --------------------------------------------------------------------

	/**
	* Returns an object with field data
	*
	* @param string $table
	* @return array
	*/
	public function field_data($table)
	{
	if (strpos($table, '.') !== FALSE)
	{
	sscanf($table, '%[^.].%s', $owner, $table);
	}
	else
	{
	$owner = $this->username;
	}

	$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHAR_LENGTH, DATA_PRECISION, DATA_LENGTH, DATA_DEFAULT, NULLABLE
	FROM ALL_TAB_COLUMNS
	WHERE UPPER(OWNER) = '.$this->escape(strtoupper($owner)).'
	AND UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));

	if (($query = $this->query($sql)) === FALSE)
	{
	return FALSE;
	}
	$query = $query->result_object();

	$retval = array();
	for ($i = 0, $c = count($query); $i < $c; $i++)
	{
	$retval[$i] = new stdClass();
	$retval[$i]->name = $query[$i]->COLUMN_NAME;
	$retval[$i]->type = $query[$i]->DATA_TYPE;

	$length = ($query[$i]->CHAR_LENGTH > 0)
	? $query[$i]->CHAR_LENGTH : $query[$i]->DATA_PRECISION;
	if ($length === NULL)
	{
	$length = $query[$i]->DATA_LENGTH;
	}
	$retval[$i]->max_length = $length;

	$default = $query[$i]->DATA_DEFAULT;
	if ($default === NULL && $query[$i]->NULLABLE === 'N')
	{
	$default = '';
	}
	$retval[$i]->default = $default;
	}

	return $retval;
	}

	// --------------------------------------------------------------------

	/**
	* Error
	*
	* Returns an array containing code and message of the last
	* database error that has occurred.
	*
	* @return array
	*/
	public function error()
	{
	// oci_error() returns an array that already contains
	// 'code' and 'message' keys, but it can return false
	// if there was no error ....
	if (is_resource($this->curs_id))
	{
	$error = oci_error($this->curs_id);
	}
	elseif (is_resource($this->stmt_id))
	{
	$error = oci_error($this->stmt_id);
	}
	elseif (is_resource($this->conn_id))
	{
	$error = oci_error($this->conn_id);
	}
	else
	{
	$error = oci_error();
	}

	return is_array($error)
	? $error
	: array('code' => '', 'message' => '');
	}

	// --------------------------------------------------------------------

	/**
	* Insert batch statement
	*
	* Generates a platform-specific insert string from the supplied data
	*
	* @param string $table Table name
	* @param array $keys INSERT keys
	* @param array $values INSERT values
	* @return string
	*/
	protected function _insert_batch($table, $keys, $values)
	{
	$keys = implode(', ', $keys);
	$sql = "INSERT ALL\n";

	for ($i = 0, $c = count($values); $i < $c; $i++)
	{
	$sql .= ' INTO '.$table.' ('.$keys.') VALUES '.$values[$i]."\n";
	}

	return $sql.'SELECT * FROM dual';
	}

	// --------------------------------------------------------------------

	/**
	* Truncate statement
	*
	* Generates a platform-specific truncate string from the supplied data
	*
	* If the database does not support the TRUNCATE statement,
	* then this method maps to 'DELETE FROM table'
	*
	* @param string $table
	* @return string
	*/
	protected function _truncate($table)
	{
	return 'TRUNCATE TABLE '.$table;
	}

	// --------------------------------------------------------------------

	/**
	* Delete statement
	*
	* Generates a platform-specific delete string from the supplied data
	*
	* @param string $table
	* @return string
	*/
	protected function _delete($table)
	{
	if ($this->qb_limit)
	{
	$this->where('rownum <= ',$this->qb_limit, FALSE);
	$this->qb_limit = FALSE;
	}

	return parent::_delete($table);
	}

	// --------------------------------------------------------------------

	/**
	* LIMIT
	*
	* Generates a platform-specific LIMIT clause
	*
	* @param string $sql SQL Query
	* @return string
	*/
	protected function _limit($sql)
	{
	if (version_compare($this->version(), '12.1', '>='))
	{
	// OFFSET-FETCH can be used only with the ORDER BY clause
	empty($this->qb_orderby) && $sql .= ' ORDER BY 1';

	return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
	}

	$this->limit_used = TRUE;
	return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
	.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1) : '');
	}

	// --------------------------------------------------------------------

	/**
	* Close DB Connection
	*
	* @return void
	*/
	protected function _close()
	{
	oci_close($this->conn_id);
	}

	// --------------------------------------------------------------------

	/**
	* We need to reset our $limit_used hack flag, so it doesn't propagate
	* to subsequent queries.
	*
	* @return void
	*/
	protected function _reset_select()
	{
	$this->limit_used = FALSE;
	parent::_reset_select();
	}
	}