summaryrefslogtreecommitdiffstats
path: root/system/database/DB_driver.php
diff options
context:
space:
mode:
authorFlorian Pritz <bluewind@xssn.at>2010-02-06 23:14:56 +0100
committerFlorian Pritz <bluewind@xssn.at>2010-02-06 23:31:27 +0100
commit9e9d77b4072de4f8c73e8bbade07a8f27734e4bd (patch)
treea5d709254968fed8f3acdb9eec68fde2faa14b94 /system/database/DB_driver.php
Initial commit
Signed-off-by: Florian Pritz <bluewind@xssn.at>
Diffstat (limited to 'system/database/DB_driver.php')
-rw-r--r--system/database/DB_driver.php1366
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 */ \ No newline at end of file