/system/database/DB_driver.php
PHP | 1406 lines | 713 code | 204 blank | 489 comment | 123 complexity | 910f80c23a57510a3db64b5035e9fcd0 MD5 | raw file
- <?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
- /**
- * CodeIgniter
- *
- * An open source application development framework for PHP 5.1.6 or newer
- *
- * NOTICE OF LICENSE
- *
- * Licensed under the Open Software License version 3.0
- *
- * This source file is subject to the Open Software License (OSL 3.0) that is
- * bundled with this package in the files license.txt / license.rst. It is
- * also available through the world wide web at this URL:
- * http://opensource.org/licenses/OSL-3.0
- * If you did not receive a copy of the license and are unable to obtain it
- * through the world wide web, please send an email to
- * licensing@ellislab.com so we can send you a copy immediately.
- *
- * @package CodeIgniter
- * @author EllisLab Dev Team
- * @copyright Copyright (c) 2008 - 2011, EllisLab, Inc. (http://ellislab.com/)
- * @license http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
- * @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 EllisLab 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.
- $driver_version_exceptions = array('oci8', 'sqlite', 'cubrid', 'pdo');
-
- if (in_array($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 == '')
- {
- log_message('error', 'Invalid query: '.$sql);
-
- if ($this->db_debug)
- {
- 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", $sql);
- }
-
- // Is query caching enabled? If the query is a "read type"
- // we will load the caching class and return the previously
- // cached query if it exists
- if ($this->cache_on == TRUE AND stristr($sql, 'SELECT'))
- {
- if ($this->_cache_init())
- {
- $this->load_rdriver();
- if (FALSE !== ($cache = $this->CACHE->read($sql)))
- {
- return $cache;
- }
- }
- }
-
- // Compile binds if needed
- if ($binds !== FALSE)
- {
- $sql = $this->compile_binds($sql, $binds);
- }
-
- // Save the query for debugging
- if ($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;
-
- // 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 = $this->_error_message();
-
- // Log errors
- log_message('error', 'Query error: '.$error_msg);
-
- if ($this->db_debug)
- {
- // 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();
-
- // Display errors
- 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 ';
- $key = $this->_protect_identifiers($key);
-
- 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_' : $this->dbdriver.'_';
-
- if (FALSE === strpos($driver, $function))
- {
- $function = $driver.$function;
- }
-
- if ( ! function_exists($function))
- {
- if ($this->db_debug)
- {
- return $this->display_error('db_unsupported_function');
- }
- return FALSE;
- }
- else
- {
- $args = (func_num_args() > 1) ? array_splice(func_get_args(), 1) : null;
-
- return call_user_func_array($function, $args);
- }
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Set Cache Directory Path
- *
- * @access public
- * @param string the path to the cache directory
- * @return void
- */
- function cache_set_path($path = '')
- {
- $this->cachedir = $path;
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Enable Query Caching
- *
- * @access public
- * @return void
- */
- function cache_on()
- {
- $this->cache_on = TRUE;
- return TRUE;
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Disable Query Caching
- *
- * @access public
- * @return void
- */
- function cache_off()
- {
- $this->cache_on = FALSE;
- return FALSE;
- }
-
-
- // --------------------------------------------------------------------
-
- /**
- * Delete the cache files associated with a particular URI
- *
- * @access public
- * @return void
- */
- function cache_delete($segment_one = '', $segment_two = '')
- {
- if ( ! $this->_cache_init())
- {
- return FALSE;
- }
- return $this->CACHE->delete($segment_one, $segment_two);
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Delete All cache files
- *
- * @access public
- * @return void
- */
- function cache_delete_all()
- {
- if ( ! $this->_cache_init())
- {
- return FALSE;
- }
-
- return $this->CACHE->delete_all();
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Initialize the Cache Class
- *
- * @access private
- * @return void
- */
- function _cache_init()
- {
- if (is_object($this->CACHE) AND class_exists('CI_DB_Cache'))
- {
- return TRUE;
- }
-
- if ( ! class_exists('CI_DB_Cache'))
- {
- if ( ! @include(BASEPATH.'database/DB_cache.php'))
- {
- return $this->cache_off();
- }
- }
-
- $this->CACHE = new CI_DB_Cache($this); // pass db object to support multiple db connections and returned db objects
- return TRUE;
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Close DB Connection
- *
- * @access public
- * @return void
- */
- function close()
- {
- if (is_resource($this->conn_id) OR is_object($this->conn_id))
- {
- $this->_close($this->conn_id);
- }
- $this->conn_id = FALSE;
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Display an error message
- *
- * @access public
- * @param string the error message
- * @param string any "swap" values
- * @param boolean whether to localize the message
- * @return string sends the application/error_db.php template
- */
- function display_error($error = '', $swap = '', $native = FALSE)
- {
- $LANG =& load_class('Lang', 'core');
- $LANG->load('db');
-
- $heading = $LANG->line('db_error_heading');
-
- if ($native == TRUE)
- {
- $message = (array) $error;
- }
- else
- {
- $message = ( ! is_array($error)) ? array(str_replace('%s', $swap, $LANG->line($error))) : $error;
- }
-
- // Find the most likely culprit of the error by going through
- // the backtrace until the source file is no longer in the
- // database folder.
-
- $trace = debug_backtrace();
-
- foreach ($trace as $call)
- {
- if (isset($call['file']) && strpos($call['file'], BASEPATH.'database') === FALSE)
- {
- // Found it - use a relative path for safety
- $message[] = 'Filename: '.str_replace(array(BASEPATH, APPPATH), '', $call['file']);
- $message[] = 'Line Number: '.$call['line'];
-
- break;
- }
- }
-
- $error =& load_class('Exceptions', 'core');
- echo $error->show_error($heading, $message, 'error_db');
- exit;
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Protect Identifiers
- *
- * This function adds backticks if appropriate based on db type
- *
- * @access private
- * @param mixed the item to escape
- * @return mixed the item with backticks
- */
- function protect_identifiers($item, $prefix_single = FALSE)
- {
- return $this->_protect_identifiers($item, $prefix_single);
- }
-
- // --------------------------------------------------------------------
-
- /**
- * Protect Identifiers
- *
- * This function is used extensively by the Active Record class, and by
- * a couple functions in this class.
- * It takes a column or table name (optionally with an alias) and inserts
- * the table prefix onto it. Some logic is necessary in order to deal with
- * column names that include the path. Consider a query like this:
- *
- * SELECT * FROM hostname.database.table.column AS c FROM hostname.database.table
- *
- * Or a query with aliasing:
- *
- * SELECT m.member_id, m.member_name FROM members AS m
- *
- * Since the column name can include up to four segments (host, DB, table, column)
- * or also have an alias prefix, we need to do a bit of work to figure this out and
- * insert the table prefix (if it exists) in the proper position, and escape only
- * the correct identifiers.
- *
- * @access private
- * @param string
- * @param bool
- * @param mixed
- * @param bool
- * @return string
- */
- function _protect_identifiers($item, $prefix_single = FALSE, $protect_identifiers = NULL, $field_exists = TRUE)
- {
- if ( ! is_bool($protect_identifiers))
- {
- $protect_identifiers = $this->_protect_identifiers;
- }
-
- if (is_array($item))
- {
- $escaped_array = array();
-
- foreach ($item as $k => $v)
- {
- $escaped_array[$this->_protect_identifiers($k)] = $this->_protect_identifiers($v);
- }
-
- return $escaped_array;
- }
-
- // Convert tabs or multiple spaces into single spaces
- $item = preg_replace('/[\t ]+/', ' ', $item);
-
- // If the item has an alias declaration we remove it and set it aside.
- // Basically we remove everything to the right of the first space
- $alias = '';
- if (strpos($item, ' ') !== FALSE)
- {
- $alias = strstr($item, " ");
- $item = substr($item, 0, - strlen($alias));
- }
-
- // This is basically a bug fix for queries that use MAX, MIN, etc.
- // If a parenthesis is found we know that we do not need to
- // escape the data or add a prefix. There's probably a more graceful
- // way to deal with this, but I'm not thinking of it -- Rick
- if (strpos($item, '(') !== FALSE)
- {
- return $item.$alias;
- }
-
- // Break the string apart if it contains periods, then insert the table prefix
- // in the correct location, assuming the period doesn't indicate that we're dealing
- // with an alias. While we're at it, we will escape the components
- if (strpos($item, '.') !== FALSE)
- {
- $parts = explode('.', $item);
-
- // Does the first segment of the exploded item match
- // one of the aliases previously identified? If so,
- // we have nothing more to do other than escape the item
- if (in_array($parts[0], $this->ar_aliased_tables))
- {
- if ($protect_identifiers === TRUE)
- {
- foreach ($parts as $key => $val)
- {
- if ( ! in_array($val, $this->_reserved_identifiers))
- {
- $parts[$key] = $this->_escape_identifiers($val);
- }
- }
-
- $item = implode('.', $parts);
- }
- return $item.$alias;
- }
-
- // Is there a table prefix defined in the config file? If not, no need to do anything
- if ($this->dbprefix != '')
- {
- // We now add the table prefix based on some logic.
- // Do we have 4 segments (hostname.database.table.column)?
- // If so, we add the table prefix to the column name in the 3rd segment.
- if (isset($parts[3]))
- {
- $i = 2;
- }
- // Do we have 3 segments (database.table.column)?
- // If so, we add the table prefix to the column name in 2nd position
- elseif (isset($parts[2]))
- {
- $i = 1;
- }
- // Do we have 2 segments (table.column)?
- // If so, we add the table prefix to the column name in 1st segment
- else
- {
- $i = 0;
- }
-
- // This flag is set when the supplied $item does not contain a field name.
- // This can happen when this function is being called from a JOIN.
- if ($field_exists == FALSE)
- {
- $i++;
- }
-
- // Verify table prefix and replace if necessary
- if ($this->swap_pre != '' && strncmp($parts[$i], $this->swap_pre, strlen($this->swap_pre)) === 0)
- {
- $parts[$i] = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $parts[$i]);
- }
-
- // We only add the table prefix if it does not already exist
- if (substr($parts[$i], 0, strlen($this->dbprefix)) != $this->dbprefix)
- {
- $parts[$i] = $this->dbprefix.$parts[$i];
- }
-
- // Put the parts back together
- $item = implode('.', $parts);
- }
-
- if ($protect_identifiers === TRUE)
- {
- $item = $this->_escape_identifiers($item);
- }
-
- return $item.$alias;
- }
-
- // Is there a table prefix? If not, no need to insert it
- if ($this->dbprefix != '')
- {
- // Verify table prefix and replace if necessary
- if ($this->swap_pre != '' && strncmp($item, $this->swap_pre, strlen($this->swap_pre)) === 0)
- {
- $item = preg_replace("/^".$this->swap_pre."(\S+?)/", $this->dbprefix."\\1", $item);
- }
-
- // Do we prefix an item with no segments?
- if ($prefix_single == TRUE AND substr($item, 0, strlen($this->dbprefix)) != $this->dbprefix)
- {
- $item = $this->dbprefix.$item;
- }
- }
-
- if ($protect_identifiers === TRUE AND ! in_array($item, $this->_reserved_identifiers))
- {
- $item = $this->_escape_identifiers($item);
- }
-
- return $item.$alias;
- }
-
-
- }
-
-
- /* End of file DB_driver.php */
- /* Location: ./system/database/DB_driver.php */