source: sourcecode/system/database/drivers/pdo/pdo_driver.php @ 1

<?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 2.1.2
 * @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}";
                }
                elseif (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 = '!';
                }

                empty($this->database) OR $this->hostname .= ';dbname='.$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()
        {
                $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 = $this->conn_id->prepare($sql);
                $result_id->execute();
                
                if (is_object($result_id))
                {
                        if (is_numeric(stripos($sql, 'SELECT')))
                        {
                                $this->affect_rows = count($result_id->fetchAll());
                                $result_id->execute();
                        }
                        else
                        {
                                $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 */