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Diffstat (limited to 'system/database/DB_driver.php')
| -rw-r--r-- | system/database/DB_driver.php | 1366 |
1 files changed, 1366 insertions, 0 deletions
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php new file mode 100644 index 000000000..014dfd44e --- /dev/null +++ b/system/database/DB_driver.php @@ -0,0 +1,1366 @@ +<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); +/** + * CodeIgniter + * + * An open source application development framework for PHP 4.3.2 or newer + * + * @package CodeIgniter + * @author ExpressionEngine Dev Team + * @copyright Copyright (c) 2008 - 2009, 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 $limit_used; + + + + /** + * Constructor. Accepts one parameter containing the database + * connection settings. + * + * @param array + */ + function CI_DB_driver($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 $this->display_error('db_unsupported_function'); + } + return FALSE; + } + + if ($this->dbdriver == 'oci8') + { + return $sql; + } + + $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", $sql); + } + + // Is query caching enabled? If the query is a "read type" + // we will load the caching class and return the previously + // cached query if it exists + if ($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 + $this->_trans_status = FALSE; + + if ($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($driver)) + { + include_once(BASEPATH.'database/DB_result'.EXT); + include_once(BASEPATH.'database/drivers/'.$this->dbdriver.'/'.$this->dbdriver.'_result'.EXT); + } + + 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 = $this->_list_columns($this->_protect_identifiers($table, TRUE, NULL, FALSE)))) + { + if ($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_' : $this->dbdriver.'_'; + + if (FALSE === strpos($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'.EXT)) + { + 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('Language'); + $LANG->load('db'); + + $heading = $LANG->line('db_error_heading'); + + if ($native == TRUE) + { + $message = $error; + } + else + { + $message = ( ! is_array($error)) ? array(str_replace('%s', $swap, $LANG->line($error))) : $error; + } + + $error =& load_class('Exceptions'); + 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 */
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