<?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
 * @copyright   Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license     http://codeigniter.com/user_guide/license.html
 * @author      EllisLab Dev Team
 * @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      EllisLab 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;

    var $options = array();

    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 = '';

            //Prior to this version, the charset can't be set in the dsn
            if(is_php('5.3.6'))
            {
                $this->hostname .= ";charset={$this->char_set}";
            }

            //Set the charset with the connection options
            $this->options['PDO::MYSQL_ATTR_INIT_COMMAND'] = "SET NAMES {$this->char_set}";
        }
        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 = '!';
        }

        $this->hostname = 'mysql:dbname='.$this->database.';host='.$this->hostname;

        $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()
    {
        $this->options['PDO::ATTR_ERRMODE'] = PDO::ERRMODE_SILENT;

        return new PDO($this->hostname, $this->username, $this->password, $this->options);
    }

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

    /**
     * Persistent database connection
     *
     * @access  private called by the base class
     * @return  resource
     */
    function db_pconnect()
    {
        $this->options['PDO::ATTR_ERRMODE'] = PDO::ERRMODE_SILENT;
        $this->options['PDO::ATTR_PERSISTENT'] = TRUE;

        return new PDO($this->hostname, $this->username, $this->password, $this->options);
    }

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

    /**
     * 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.
        $this->_trans_failure = (bool) ($test_mode === TRUE);

        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 */