<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**

* CodeIgniter

*

* An open source application development framework for PHP 5.1.6 or newer

*

* @package CodeIgniter

* @author ExpressionEngine Dev Team

* @copyright Copyright (c) 2008 - 2011, EllisLab, Inc.

* @license http://codeigniter.com/user_guide/license.html

* @link http://codeigniter.com

* @since Version 1.0

* @filesource

*/

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

/**

* Database Driver Class

*

* This is the platform-independent base DB implementation class.

* This class will not be called directly. Rather, the adapter

* class for the specific database will extend and instantiate it.

*

* @package CodeIgniter

* @subpackage Drivers

* @category Database

* @author ExpressionEngine Dev Team

* @link http://codeigniter.com/user_guide/database/

*/

class CI_DB_driver {

var $username;

var $password;

var $hostname;

var $database;

var $dbdriver = 'mysql';

var $dbprefix = '';

var $char_set = 'utf8';

var $dbcollat = 'utf8_general_ci';

var $autoinit = TRUE; // Whether to automatically initialize the DB

var $swap_pre = '';

var $port = '';

var $pconnect = FALSE;

var $conn_id = FALSE;

var $result_id = FALSE;

var $db_debug = FALSE;

var $benchmark = 0;

var $query_count = 0;

var $bind_marker = '?';

var $save_queries = TRUE;

var $queries = array();

var $query_times = array();

var $data_cache = array();

var $trans_enabled = TRUE;

var $trans_strict = TRUE;

var $_trans_depth = 0;

var $_trans_status = TRUE; // Used with transactions to determine if a rollback should occur

var $cache_on = FALSE;

var $cachedir = '';

var $cache_autodel = FALSE;

var $CACHE; // The cache class object

// Private variables

var $_protect_identifiers = TRUE;

var $_reserved_identifiers = array('*'); // Identifiers that should NOT be escaped

// These are use with Oracle

var $stmt_id;

var $curs_id;

var $limit_used;

/**

* Constructor. Accepts one parameter containing the database

* connection settings.

*

* @param array

*/

function __construct($params)

{

if (is_array($params))

{

foreach ($params as $key => $val)

{

$this->$key = $val;

}

}

log_message('debug', 'Database Driver Class Initialized');

}

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

/**

* Initialize Database Settings

*

* @access private Called by the constructor

* @param mixed

* @return void

*/

function initialize()

{

// If an existing connection resource is available

// there is no need to connect and select the database

if (is_resource($this->conn_id) OR is_object($this->conn_id))

{

return TRUE;

}

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

// Connect to the database and set the connection ID

$this->conn_id = ($this->pconnect == FALSE) ? $this->db_connect() : $this->db_pconnect();

// No connection resource? Throw an error

if ( ! $this->conn_id)

{

log_message('error', 'Unable to connect to the database');

if ($this->db_debug)

{

$this->display_error('db_unable_to_connect');

}

return FALSE;

}

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

// Select the DB... assuming a database name is specified in the config file

if ($this->database != '')

{

if ( ! $this->db_select())

{

log_message('error', 'Unable to select database: '.$this->database);

if ($this->db_debug)

{

$this->display_error('db_unable_to_select', $this->database);

}

return FALSE;

}

else

{

// We've selected the DB. Now we set the character set

if ( ! $this->db_set_charset($this->char_set, $this->dbcollat))

{

return FALSE;

}

return TRUE;

}

}

return TRUE;

}

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

/**

* Set client character set

*

* @access public

* @param string

* @param string

* @return resource

*/

function db_set_charset($charset, $collation)

{

if ( ! $this->_db_set_charset($this->char_set, $this->dbcollat))

{

log_message('error', 'Unable to set database connection charset: '.$this->char_set);

if ($this->db_debug)

{

$this->display_error('db_unable_to_set_charset', $this->char_set);

}

return FALSE;

}

return TRUE;

}

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

/**

* The name of the platform in use (mysql, mssql, etc...)

*

* @access public

* @return string

*/

function platform()

{

return $this->dbdriver;

}

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

/**

* Database Version Number. Returns a string containing the

* version of the database being used

*

* @access public

* @return string

*/

function version()

{

if (FALSE === ($sql = $this->_version()))

{

if ($this->db_debug)

{

return $this->display_error('db_unsupported_function');

}

return FALSE;

}

// Some DBs have functions that return the version, and don't run special

// SQL queries per se. In these instances, just return the result.

$driver_version_exceptions = array('oci8', 'sqlite', 'cubrid');

if (in_array($this->dbdriver, $driver_version_exceptions))

{

return $sql;

}

else

{

$query = $this->query($sql);

return $query->row('ver');

}

}

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

/**

* Execute the query

*

* Accepts an SQL string as input and returns a result object upon

* successful execution of a "read" type query. Returns boolean TRUE

* upon successful execution of a "write" type query. Returns boolean

* FALSE upon failure, and if the $db_debug variable is set to TRUE

* will raise an error.

*

* @access public

* @param string An SQL query string

* @param array An array of binding data

* @return mixed

*/

function query($sql, $binds = FALSE, $return_object = TRUE)

{

if ($sql == '')

{

if ($this->db_debug)

{

log_message('error', 'Invalid query: '.$sql);

return $this->display_error('db_invalid_query');

}

return FALSE;

}

// Verify table prefix and replace if necessary

if ( ($this->dbprefix != '' AND $this->swap_pre != '') AND ($this->dbprefix != $this->swap_pre) )

{

$sql = preg_replace("/(\W)".$this->swap_pre."(\S+?)/", "\\1".$this->dbprefix."\\2", $sql);

}

// Compile binds if needed

if ($binds !== FALSE)

{

$sql = $this->compile_binds($sql, $binds);

}

// Is query caching enabled? If the query is a "read type"

// we will load the caching class and return the previously

// cached query if it exists

if ($this->cache_on == TRUE AND stristr($sql, 'SELECT'))

{

if ($this->_cache_init())

{

$this->load_rdriver();

if (FALSE !== ($cache = $this->CACHE->read($sql)))

{

return $cache;

}

}

}

// Save the query for debugging

if ($this->save_queries == TRUE)

{

$this->queries[] = $sql;

}

// Start the Query Timer

$time_start = list($sm, $ss) = explode(' ', microtime());

// Run the Query

if (FALSE === ($this->result_id = $this->simple_query($sql)))

{

if ($this->save_queries == TRUE)

{

$this->query_times[] = 0;

}

// This will trigger a rollback if transactions are being used

$this->_trans_status = FALSE;

if ($this->db_debug)

{

// grab the error number and message now, as we might run some

// additional queries before displaying the error

$error_no = $this->_error_number();

$error_msg = $this->_error_message();

// We call this function in order to roll-back queries

// if transactions are enabled. If we don't call this here

// the error message will trigger an exit, causing the

// transactions to remain in limbo.

$this->trans_complete();

// Log and display errors

log_message('error', 'Query error: '.$error_msg);

return $this->display_error(

array(

'Error Number: '.$error_no,

$error_msg,

$sql

)

);

}

return FALSE;

}

// Stop and aggregate the query time results

$time_end = list($em, $es) = explode(' ', microtime());

$this->benchmark += ($em + $es) - ($sm + $ss);

if ($this->save_queries == TRUE)

{

$this->query_times[] = ($em + $es) - ($sm + $ss);

}

// Increment the query counter

$this->query_count++;

// Was the query a "write" type?

// If so we'll simply return true

if ($this->is_write_type($sql) === TRUE)

{

// If caching is enabled we'll auto-cleanup any

// existing files related to this particular URI

if ($this->cache_on == TRUE AND $this->cache_autodel == TRUE AND $this->_cache_init())

{

$this->CACHE->delete();

}

return TRUE;

}

// Return TRUE if we don't need to create a result object

// Currently only the Oracle driver uses this when stored

// procedures are used

if ($return_object !== TRUE)

{

return TRUE;

}

// Load and instantiate the result driver

$driver = $this->load_rdriver();

$RES = new $driver();

$RES->conn_id = $this->conn_id;

$RES->result_id = $this->result_id;

if ($this->dbdriver == 'oci8')

{

$RES->stmt_id = $this->stmt_id;

$RES->curs_id = NULL;

$RES->limit_used = $this->limit_used;

$this->stmt_id = FALSE;

}

// oci8 vars must be set before calling this

$RES->num_rows = $RES->num_rows();

// Is query caching enabled? If so, we'll serialize the

// result object and save it to a cache file.

if ($this->cache_on == TRUE AND $this->_cache_init())

{

// We'll create a new instance of the result object

// only without the platform specific driver since

// we can't use it with cached data (the query result

// resource ID won't be any good once we've cached the

// result object, so we'll have to compile the data

// and save it)

$CR = new CI_DB_result();

$CR->num_rows = $RES->num_rows();

$CR->result_object = $RES->result_object();

$CR->result_array = $RES->result_array();

// Reset these since cached objects can not utilize resource IDs.

$CR->conn_id = NULL;

$CR->result_id = NULL;

$this->CACHE->write($sql, $CR);

}

return $RES;

}

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

/**

* Load the result drivers

*

* @access public

* @return string the name of the result class

*/

function load_rdriver()

{

$driver = 'CI_DB_'.$this->dbdriver.'_result';

if ( ! class_exists($driver))

{

include_once(BASEPATH.'database/DB_result.php');

include_once(BASEPATH.'database/drivers/'.$this->dbdriver.'/'.$this->dbdriver.'_result.php');

}

return $driver;

}

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

/**

* Simple Query

* This is a simplified version of the query() function. Internally

* we only use it when running transaction commands since they do

* not require all the features of the main query() function.

*

* @access public

* @param string the sql query

* @return mixed

*/

function simple_query($sql)

{

if ( ! $this->conn_id)

{

$this->initialize();

}

return $this->_execute($sql);

}

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

/**

* Disable Transactions

* This permits transactions to be disabled at run-time.

*

* @access public

* @return void

*/

function trans_off()

{

$this->trans_enabled = FALSE;

}

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

/**

* Enable/disable Transaction Strict Mode

* When strict mode is enabled, if you are running multiple groups of

* transactions, if one group fails all groups will be rolled back.

* If strict mode is disabled, each group is treated autonomously, meaning

* a failure of one group will not affect any others

*

* @access public

* @return void

*/

function trans_strict($mode = TRUE)

{

$this->trans_strict = is_bool($mode) ? $mode : TRUE;

}

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

/**

* Start Transaction

*

* @access public

* @return void

*/

function trans_start($test_mode = FALSE)

{

if ( ! $this->trans_enabled)

{

return FALSE;

}

// When transactions are nested we only begin/commit/rollback the outermost ones

if ($this->_trans_depth > 0)

{

$this->_trans_depth += 1;

return;

}

$this->trans_begin($test_mode);

}

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

/**

* Complete Transaction

*

* @access public

* @return bool

*/

function trans_complete()

{

if ( ! $this->trans_enabled)

{

return FALSE;

}

// When transactions are nested we only begin/commit/rollback the outermost ones

if ($this->_trans_depth > 1)

{

$this->_trans_depth -= 1;

return TRUE;

}

// The query() function will set this flag to FALSE in the event that a query failed

if ($this->_trans_status === FALSE)

{

$this->trans_rollback();

// If we are NOT running in strict mode, we will reset

// the _trans_status flag so that subsequent groups of transactions

// will be permitted.

if ($this->trans_strict === FALSE)

{

$this->_trans_status = TRUE;

}

log_message('debug', 'DB Transaction Failure');

return FALSE;

}

$this->trans_commit();

return TRUE;

}

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

/**

* Lets you retrieve the transaction flag to determine if it has failed

*

* @access public

* @return bool

*/

function trans_status()

{

return $this->_trans_status;

}

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

/**

* Compile Bindings

*

* @access public

* @param string the sql statement

* @param array an array of bind data

* @return string

*/

function compile_binds($sql, $binds)

{

if (strpos($sql, $this->bind_marker) === FALSE)

{

return $sql;

}

if ( ! is_array($binds))

{

$binds = array($binds);

}

// Get the sql segments around the bind markers

$segments = explode($this->bind_marker, $sql);

// The count of bind should be 1 less then the count of segments

// If there are more bind arguments trim it down

if (count($binds) >= count($segments)) {

$binds = array_slice($binds, 0, count($segments)-1);

}

// Construct the binded query

$result = $segments[0];

$i = 0;

foreach ($binds as $bind)

{

$result .= $this->escape($bind);

$result .= $segments[++$i];

}

return $result;

}

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

/**

* Determines if a query is a "write" type.

*

* @access public

* @param string An SQL query string

* @return boolean

*/

function is_write_type($sql)

{

if ( ! preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK)\s+/i', $sql))

{

return FALSE;

}

return TRUE;

}

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

/**

* Calculate the aggregate query elapsed time

*

* @access public

* @param integer The number of decimal places

* @return integer

*/

function elapsed_time($decimals = 6)

{

return number_format($this->benchmark, $decimals);

}

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

/**

* Returns the total number of queries

*

* @access public

* @return integer

*/

function total_queries()

{

return $this->query_count;

}

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

/**

* Returns the last query that was executed

*

* @access public

* @return void

*/

function last_query()

{

return end($this->queries);

}

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

/**

* "Smart" Escape String

*

* Escapes data based on type

* Sets boolean and null types

*

* @access public

* @param string

* @return mixed

*/

function escape($str)

{

if (is_string($str))

{

$str = "'".$this->escape_str($str)."'";

}

elseif (is_bool($str))

{

$str = ($str === FALSE) ? 0 : 1;

}

elseif (is_null($str))

{

$str = 'NULL';

}

return $str;

}

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

/**

* Escape LIKE String

*

* Calls the individual driver for platform

* specific escaping for LIKE conditions

*

* @access public

* @param string

* @return mixed

*/

function escape_like_str($str)

{

return $this->escape_str($str, TRUE);

}

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

/**

* Primary

*

* Retrieves the primary key. It assumes that the row in the first

* position is the primary key

*

* @access public

* @param string the table name

* @return string

*/

function primary($table = '')

{

$fields = $this->list_fields($table);

if ( ! is_array($fields))

{

return FALSE;

}

return current($fields);

}

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

/**

* Returns an array of table names

*

* @access public

* @return array

*/

function list_tables($constrain_by_prefix = FALSE)

{

// Is there a cached result?

if (isset($this->data_cache['table_names']))

{

return $this->data_cache['table_names'];

}

if (FALSE === ($sql = $this->_list_tables($constrain_by_prefix)))

{

if ($this->db_debug)

{

return $this->display_error('db_unsupported_function');

}

return FALSE;

}

$retval = array();

$query = $this->query($sql);

if ($query->num_rows() > 0)

{

foreach ($query->result_array() as $row)

{

if (isset($row['TABLE_NAME']))

{

$retval[] = $row['TABLE_NAME'];

}

else

{

$retval[] = array_shift($row);

}

}

}

$this->data_cache['table_names'] = $retval;

return $this->data_cache['table_names'];

}

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

/**

* Determine if a particular table exists

* @access public

* @return boolean

*/

function table_exists($table_name)

{

return ( ! in_array($this->_protect_identifiers($table_name, TRUE, FALSE, FALSE), $this->list_tables())) ? FALSE : TRUE;

}

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

/**

* Fetch MySQL Field Names

*

* @access public

* @param string the table name

* @return array

*/

function list_fields($table = '')

{

// Is there a cached result?

if (isset($this->data_cache['field_names'][$table]))

{

return $this->data_cache['field_names'][$table];

}

if ($table == '')

{

if ($this->db_debug)

{

return $this->display_error('db_field_param_missing');

}

return FALSE;

}

if (FALSE === ($sql = $this->_list_columns($table)))

{

if ($this->db_debug)

{

return $this->display_error('db_unsupported_function');

}

return FALSE;

}

$query = $this->query($sql);

$retval = array();

foreach ($query->result_array() as $row)

{

if (isset($row['COLUMN_NAME']))

{

$retval[] = $row['COLUMN_NAME'];

}

else

{

$retval[] = current($row);

}

}

$this->data_cache['field_names'][$table] = $retval;

return $this->data_cache['field_names'][$table];

}

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

/**

* Determine if a particular field exists

* @access public

* @param string

* @param string

* @return boolean

*/

function field_exists($field_name, $table_name)

{

return ( ! in_array($field_name, $this->list_fields($table_name))) ? FALSE : TRUE;

}

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

/**

* Returns an object with field data

*

* @access public

* @param string the table name

* @return object

*/

function field_data($table = '')

{

if ($table == '')

{

if ($this->db_debug)

{

return $this->display_error('db_field_param_missing');

}

return FALSE;

}

$query = $this->query($this->_field_data($this->_protect_identifiers($table, TRUE, NULL, FALSE)));

return $query->field_data();

}

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

/**

* Generate an insert string

*

* @access public

* @param string the table upon which the query will be performed

* @param array an associative array data of key/values

* @return string

*/

function insert_string($table, $data)

{

$fields = array();

$values = array();

foreach ($data as $key => $val)

{

$fields[] = $this->_escape_identifiers($key);

$values[] = $this->escape($val);

}

return $this->_insert($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $values);

}

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

/**

* Generate an update string

*

* @access public

* @param string the table upon which the query will be performed

* @param array an associative array data of key/values

* @param mixed the "where" statement

* @return string

*/

function update_string($table, $data, $where)

{

if ($where == '')

{

return false;

}

$fields = array();

foreach ($data as $key => $val)

{

$fields[$this->_protect_identifiers($key)] = $this->escape($val);

}

if ( ! is_array($where))

{

$dest = array($where);

}

else

{

$dest = array();

foreach ($where as $key => $val)

{

$prefix = (count($dest) == 0) ? '' : ' AND ';

if ($val !== '')

{

if ( ! $this->_has_operator($key))

{

$key .= ' =';

}

$val = ' '.$this->escape($val);

}

$dest[] = $prefix.$key.$val;

}

}

return $this->_update($this->_protect_identifiers($table, TRUE, NULL, FALSE), $fields, $dest);

}

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

/**

* Tests whether the string has an SQL operator

*

* @access private

* @param string

* @return bool

*/

function _has_operator($str)

{

$str = trim($str);

if ( ! preg_match("/(\s|<|>|!|=|is null|is not null)/i", $str))

{

return FALSE;

}

return TRUE;

}

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

/**

* Enables a native PHP function to be run, using a platform agnostic wrapper.

*

* @access public

* @param string the function name

* @param mixed any parameters needed by the function

* @return mixed

*/

function call_function($function)

{

$driver = ($this->dbdriver == 'postgre') ? 'pg_' : $this->dbdriver.'_';