if statment code style update
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
new file mode 100644
index 0000000..19e069b
--- /dev/null
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -0,0 +1,792 @@
+<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 5.1.6 or newer
+ *
+ * @package		CodeIgniter
+ * @author		ExpressionEngine Dev Team
+ * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
+ * @license		http://codeigniter.com/user_guide/license.html
+ * @link		http://codeigniter.com
+ * @since		Version 2.1.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * PDO Database Adapter Class
+ *
+ * Note: _DB is an extender class that the app controller
+ * creates dynamically based on whether the active record
+ * class is being used or not.
+ *
+ * @package		CodeIgniter
+ * @subpackage	Drivers
+ * @category	Database
+ * @author		ExpressionEngine Dev Team
+ * @link		http://codeigniter.com/user_guide/database/
+ */
+class CI_DB_pdo_driver extends CI_DB {
+
+	var $dbdriver = 'pdo';
+
+	// the character used to excape - not necessary for PDO
+	var $_escape_char = '';
+	var $_like_escape_str;
+	var $_like_escape_chr;
+	
+
+	/**
+	 * The syntax to count rows is slightly different across different
+	 * database engines, so this string appears in each driver and is
+	 * used for the count_all() and count_all_results() functions.
+	 */
+	var $_count_string = "SELECT COUNT(*) AS ";
+	var $_random_keyword;
+
+
+	function __construct($params)
+	{
+		parent::__construct($params);
+		
+		// clause and character used for LIKE escape sequences
+		if (strpos($this->hostname, 'mysql') !== FALSE)
+		{
+			$this->_like_escape_str = '';
+			$this->_like_escape_chr = '';
+		}
+		else if (strpos($this->hostname, 'odbc') !== FALSE)
+		{
+			$this->_like_escape_str = " {escape '%s'} ";
+			$this->_like_escape_chr = '!';
+		}
+		else
+		{
+			$this->_like_escape_str = " ESCAPE '%s' ";
+			$this->_like_escape_chr = '!';
+		}
+		
+		$this->hostname = $this->hostname . ";dbname=".$this->database;
+		$this->trans_enabled = FALSE;
+
+		$this->_random_keyword = ' RND('.time().')'; // database specific random keyword
+	}
+
+	/**
+	 * Non-persistent database connection
+	 *
+	 * @access	private called by the base class
+	 * @return	resource
+	 */
+	function db_connect()
+	{
+		return new PDO($this->hostname,$this->username,$this->password, array(
+			PDO::ATTR_ERRMODE => PDO::ERRMODE_SILENT
+		));
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Persistent database connection
+	 *
+	 * @access	private called by the base class
+	 * @return	resource
+	 */
+	function db_pconnect()
+	{
+		return new PDO($this->hostname,$this->username,$this->password, array(
+			PDO::ATTR_ERRMODE => PDO::ERRMODE_SILENT,
+			PDO::ATTR_PERSISTENT => true
+		));
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Reconnect
+	 *
+	 * Keep / reestablish the db connection if no queries have been
+	 * sent for a length of time exceeding the server's idle timeout
+	 *
+	 * @access	public
+	 * @return	void
+	 */
+	function reconnect()
+	{
+		if ($this->db->db_debug)
+		{
+			return $this->db->display_error('db_unsuported_feature');
+		}
+		return FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Select the database
+	 *
+	 * @access	private called by the base class
+	 * @return	resource
+	 */
+	function db_select()
+	{
+		// Not needed for PDO
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Set client character set
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	string
+	 * @return	resource
+	 */
+	function db_set_charset($charset, $collation)
+	{
+		// @todo - add support if needed
+		return TRUE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Version number query string
+	 *
+	 * @access	public
+	 * @return	string
+	 */
+	function _version()
+	{
+		return $this->conn_id->getAttribute(PDO::ATTR_CLIENT_VERSION);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Execute the query
+	 *
+	 * @access	private called by the base class
+	 * @param	string	an SQL query
+	 * @return	object
+	 */
+	function _execute($sql)
+	{
+		$sql = $this->_prep_query($sql);
+		$result_id = $this->conn_id->query($sql);
+		
+		if (is_object($result_id))
+		{
+			$this->affect_rows = $result_id->rowCount();
+		}
+		else
+		{
+			$this->affect_rows = 0;
+		}
+		
+		return $result_id;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Prep the query
+	 *
+	 * If needed, each database adapter can prep the query string
+	 *
+	 * @access	private called by execute()
+	 * @param	string	an SQL query
+	 * @return	string
+	 */
+	function _prep_query($sql)
+	{
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Begin Transaction
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	function trans_begin($test_mode = FALSE)
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		// Reset the transaction failure flag.
+		// If the $test_mode flag is set to TRUE transactions will be rolled back
+		// even if the queries produce a successful result.
+		$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;
+
+		return $this->conn_id->beginTransaction();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Commit Transaction
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	function trans_commit()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		$ret = $this->conn->commit();
+		return $ret;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Rollback Transaction
+	 *
+	 * @access	public
+	 * @return	bool
+	 */
+	function trans_rollback()
+	{
+		if ( ! $this->trans_enabled)
+		{
+			return TRUE;
+		}
+
+		// When transactions are nested we only begin/commit/rollback the outermost ones
+		if ($this->_trans_depth > 0)
+		{
+			return TRUE;
+		}
+
+		$ret = $this->conn_id->rollBack();
+		return $ret;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Escape String
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	bool	whether or not the string will be used in a LIKE condition
+	 * @return	string
+	 */
+	function escape_str($str, $like = FALSE)
+	{
+		if (is_array($str))
+		{
+			foreach ($str as $key => $val)
+			{
+				$str[$key] = $this->escape_str($val, $like);
+			}
+
+			return $str;
+		}
+		
+		//Escape the string
+		$str = $this->conn_id->quote($str);
+		
+		//If there are duplicated quotes, trim them away
+		if (strpos($str, "'") === 0)
+		{
+			$str = substr($str, 1, -1);
+		}
+		
+		// escape LIKE condition wildcards
+		if ($like === TRUE)
+		{
+			$str = str_replace(	array('%', '_', $this->_like_escape_chr),
+								array($this->_like_escape_chr.'%', $this->_like_escape_chr.'_', $this->_like_escape_chr.$this->_like_escape_chr),
+								$str);
+		}
+
+		return $str;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Affected Rows
+	 *
+	 * @access	public
+	 * @return	integer
+	 */
+	function affected_rows()
+	{
+		return $this->affect_rows;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert ID
+	 * 
+	 * @access	public
+	 * @return	integer
+	 */
+	function insert_id($name=NULL)
+	{
+		//Convenience method for postgres insertid
+		if (strpos($this->hostname, 'pgsql') !== FALSE)
+		{
+			$v = $this->_version();
+
+			$table	= func_num_args() > 0 ? func_get_arg(0) : NULL;
+
+			if ($table == NULL && $v >= '8.1')
+			{
+				$sql='SELECT LASTVAL() as ins_id';
+			}
+			$query = $this->query($sql);
+			$row = $query->row();
+			return $row->ins_id;
+		}
+		else
+		{
+			return $this->conn_id->lastInsertId($name);
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * "Count All" query
+	 *
+	 * Generates a platform-specific query string that counts all records in
+	 * the specified database
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	string
+	 */
+	function count_all($table = '')
+	{
+		if ($table == '')
+		{
+			return 0;
+		}
+
+		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));
+
+		if ($query->num_rows() == 0)
+		{
+			return 0;
+		}
+
+		$row = $query->row();
+		$this->_reset_select();
+		return (int) $row->numrows;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Show table query
+	 *
+	 * Generates a platform-specific query string so that the table names can be fetched
+	 *
+	 * @access	private
+	 * @param	boolean
+	 * @return	string
+	 */
+	function _list_tables($prefix_limit = FALSE)
+	{
+		$sql = "SHOW TABLES FROM `".$this->database."`";
+
+		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
+		{
+			//$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return FALSE; // not currently supported
+		}
+
+		return $sql;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Show column query
+	 *
+	 * Generates a platform-specific query string so that the column names can be fetched
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @return	string
+	 */
+	function _list_columns($table = '')
+	{
+		return "SHOW COLUMNS FROM ".$table;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Field data query
+	 *
+	 * Generates a platform-specific query so that the column data can be retrieved
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @return	object
+	 */
+	function _field_data($table)
+	{
+		return "SELECT TOP 1 FROM ".$table;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * The error message string
+	 *
+	 * @access	private
+	 * @return	string
+	 */
+	function _error_message()
+	{
+		$error_array = $this->conn_id->errorInfo();
+		return $error_array[2];
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * The error message number
+	 *
+	 * @access	private
+	 * @return	integer
+	 */
+	function _error_number()
+	{
+		return $this->conn_id->errorCode();
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Escape the SQL Identifiers
+	 *
+	 * This function escapes column and table names
+	 *
+	 * @access	private
+	 * @param	string
+	 * @return	string
+	 */
+	function _escape_identifiers($item)
+	{
+		if ($this->_escape_char == '')
+		{
+			return $item;
+		}
+
+		foreach ($this->_reserved_identifiers as $id)
+		{
+			if (strpos($item, '.'.$id) !== FALSE)
+			{
+				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
+
+				// remove duplicates if the user already included the escape
+				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+			}
+		}
+
+		if (strpos($item, '.') !== FALSE)
+		{
+			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
+			
+		}
+		else
+		{
+			$str = $this->_escape_char.$item.$this->_escape_char;
+		}
+
+		// remove duplicates if the user already included the escape
+		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * From Tables
+	 *
+	 * This function implicitly groups FROM tables so there is no confusion
+	 * about operator precedence in harmony with SQL standards
+	 *
+	 * @access	public
+	 * @param	type
+	 * @return	type
+	 */
+	function _from_tables($tables)
+	{
+		if ( ! is_array($tables))
+		{
+			$tables = array($tables);
+		}
+
+		return (count($tables) == 1) ? $tables[0] : '('.implode(', ', $tables).')';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @param	array	the insert keys
+	 * @param	array	the insert values
+	 * @return	string
+	 */
+	function _insert($table, $keys, $values)
+	{
+		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Insert_batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data
+	 *
+	 * @access  public
+	 * @param   string  the table name
+	 * @param   array   the insert keys
+	 * @param   array   the insert values
+	 * @return  string
+	 */
+	function _insert_batch($table, $keys, $values)
+	{
+		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES ".implode(', ', $values);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Update statement
+	 *
+	 * Generates a platform-specific update string from the supplied data
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @param	array	the update data
+	 * @param	array	the where clause
+	 * @param	array	the orderby clause
+	 * @param	array	the limit clause
+	 * @return	string
+	 */
+	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	{
+		foreach ($values as $key => $val)
+		{
+			$valstr[] = $key." = ".$val;
+		}
+
+		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
+
+		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
+
+		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
+
+		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
+
+		$sql .= $orderby.$limit;
+
+		return $sql;
+	}
+	
+	// --------------------------------------------------------------------
+
+	/**
+	 * Update_Batch statement
+	 *
+	 * Generates a platform-specific batch update string from the supplied data
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @param	array	the update data
+	 * @param	array	the where clause
+	 * @return	string
+	 */
+	function _update_batch($table, $values, $index, $where = NULL)
+	{
+		$ids = array();
+		$where = ($where != '' AND count($where) >=1) ? implode(" ", $where).' AND ' : '';
+
+		foreach ($values as $key => $val)
+		{
+			$ids[] = $val[$index];
+
+			foreach (array_keys($val) as $field)
+			{
+				if ($field != $index)
+				{
+					$final[$field][] =  'WHEN '.$index.' = '.$val[$index].' THEN '.$val[$field];
+				}
+			}
+		}
+
+		$sql = "UPDATE ".$table." SET ";
+		$cases = '';
+
+		foreach ($final as $k => $v)
+		{
+			$cases .= $k.' = CASE '."\n";
+			foreach ($v as $row)
+			{
+				$cases .= $row."\n";
+			}
+
+			$cases .= 'ELSE '.$k.' END, ';
+		}
+
+		$sql .= substr($cases, 0, -2);
+
+		$sql .= ' WHERE '.$where.$index.' IN ('.implode(',', $ids).')';
+
+		return $sql;
+	}
+
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Truncate statement
+	 *
+	 * Generates a platform-specific truncate string from the supplied data
+	 * If the database does not support the truncate() command
+	 * This function maps to "DELETE FROM table"
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @return	string
+	 */
+	function _truncate($table)
+	{
+		return $this->_delete($table);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Delete statement
+	 *
+	 * Generates a platform-specific delete string from the supplied data
+	 *
+	 * @access	public
+	 * @param	string	the table name
+	 * @param	array	the where clause
+	 * @param	string	the limit clause
+	 * @return	string
+	 */
+	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	{
+		$conditions = '';
+
+		if (count($where) > 0 OR count($like) > 0)
+		{
+			$conditions = "\nWHERE ";
+			$conditions .= implode("\n", $this->ar_where);
+
+			if (count($where) > 0 && count($like) > 0)
+			{
+				$conditions .= " AND ";
+			}
+			$conditions .= implode("\n", $like);
+		}
+
+		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
+
+		return "DELETE FROM ".$table.$conditions.$limit;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Limit string
+	 *
+	 * Generates a platform-specific LIMIT clause
+	 *
+	 * @access	public
+	 * @param	string	the sql query string
+	 * @param	integer	the number of rows to limit the query to
+	 * @param	integer	the offset value
+	 * @return	string
+	 */
+	function _limit($sql, $limit, $offset)
+	{
+		if (strpos($this->hostname, 'cubrid') !== FALSE || strpos($this->hostname, 'sqlite') !== FALSE)
+		{
+			if ($offset == 0)
+			{
+				$offset = '';
+			}
+			else
+			{
+				$offset .= ", ";
+			}
+
+			return $sql."LIMIT ".$offset.$limit;
+		}
+		else
+		{
+			$sql .= "LIMIT ".$limit;
+
+			if ($offset > 0)
+			{
+				$sql .= " OFFSET ".$offset;
+			}
+			
+			return $sql;
+		}
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * Close DB Connection
+	 *
+	 * @access	public
+	 * @param	resource
+	 * @return	void
+	 */
+	function _close($conn_id)
+	{
+		$this->conn_id = null;
+	}
+
+
+}
+
+
+
+/* End of file pdo_driver.php */
+/* Location: ./system/database/drivers/pdo/pdo_driver.php */
\ No newline at end of file