oci8_driver.php

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<?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, EllisLab, Inc.
 * @license             http://codeigniter.com/user_guide/license.html
 * @link                http://codeigniter.com
 * @since               Version 1.0
 * @filesource
 */

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

/**
 * oci8 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/
 */

/**
 * oci8 Database Adapter Class
 *
 * This is a modification of the DB_driver class to
 * permit access to oracle databases
 *
 * NOTE: this uses the PHP 4 oci methods
 *
 * @author        Kelly McArdle
 *
 */

class CI_DB_oci8_driver extends CI_DB {

        var $dbdriver = 'oci8';
        
        // The character used for excaping
        var $_escape_char = '"';

        /**
         * 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(1) AS ";
        var $_random_keyword = ' ASC'; // not currently supported

        // Set "auto commit" by default
        var $_commit = OCI_COMMIT_ON_SUCCESS;

        // need to track statement id and cursor id
        var $stmt_id;
        var $curs_id;

        // if we use a limit, we will add a field that will
        // throw off num_fields later
        var $limit_used;

        /**
         * Non-persistent database connection
         *
         * @access  private called by the base class
         * @return  resource
         */
        function db_connect()
        {
                return @ocilogon($this->username, $this->password, $this->hostname);
        }

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

        /**
         * Persistent database connection
         *
         * @access  private called by the base class
         * @return  resource
         */
        function db_pconnect()
        {
                return @ociplogon($this->username, $this->password, $this->hostname);
        }

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

        /**
         * Select the database
         *
         * @access  private called by the base class
         * @return  resource
         */
        function db_select()
        {
                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 ociserverversion($this->conn_id);
        }

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

        /**
         * Execute the query
         *
         * @access  private called by the base class
         * @param   string  an SQL query
         * @return  resource
         */
        function _execute($sql)
        {
                // oracle must parse the query before it is run. All of the actions with
                // the query are based on the statement id returned by ociparse
                $this->stmt_id = FALSE;
                $this->_set_stmt_id($sql);
                ocisetprefetch($this->stmt_id, 1000);
                return @ociexecute($this->stmt_id, $this->_commit);
        }

        /**
         * Generate a statement ID
         *
         * @access  private
         * @param   string  an SQL query
         * @return  none
         */
        function _set_stmt_id($sql)
        {
                if ( ! is_resource($this->stmt_id))
                {
                        $this->stmt_id = ociparse($this->conn_id, $this->_prep_query($sql));
                }
        }

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

        /**
         * 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;
        }

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

        /**
         * getCursor.  Returns a cursor from the datbase
         *
         * @access  public
         * @return  cursor id
         */
        function get_cursor()
        {
                $this->curs_id = ocinewcursor($this->conn_id);
                return $this->curs_id;
        }

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

        /**
         * Stored Procedure.  Executes a stored procedure
         *
         * @access  public
         * @param   package      package stored procedure is in
         * @param   procedure   stored procedure to execute
         * @param   params        array of parameters
         * @return  array
         *
         * params array keys
         *
         * KEY    OPTIONAL      NOTES
         * name         no              the name of the parameter should be in :<param_name> format
         * value        no              the value of the parameter.  If this is an OUT or IN OUT parameter,
         *                                      this should be a reference to a variable
         * type         yes             the type of the parameter
         * length       yes             the max size of the parameter
         */
        function stored_procedure($package, $procedure, $params)
        {
                if ($package == '' OR $procedure == '' OR ! is_array($params))
                {
                        if ($this->db_debug)
                        {
                                log_message('error', 'Invalid query: '.$package.'.'.$procedure);
                                return $this->display_error('db_invalid_query');
                        }
                        return FALSE;
                }
                
                // build the query string
                $sql = "begin $package.$procedure(";

                $have_cursor = FALSE;
                foreach($params as $param)
                {
                        $sql .= $param['name'] . ",";
                        
                        if (array_key_exists('type', $param) && ($param['type'] == OCI_B_CURSOR))
                        {
                                $have_cursor = TRUE;
                        }
                }
                $sql = trim($sql, ",") . "); end;";
                                
                $this->stmt_id = FALSE;
                $this->_set_stmt_id($sql);
                $this->_bind_params($params);
                $this->query($sql, FALSE, $have_cursor);
        }
        
        // --------------------------------------------------------------------

        /**
         * Bind parameters
         *
         * @access  private
         * @return  none
         */
        function _bind_params($params)
        {
                if ( ! is_array($params) OR ! is_resource($this->stmt_id))
                {
                        return;
                }
                
                foreach ($params as $param)
                {
                        foreach (array('name', 'value', 'type', 'length') as $val)
                        {
                                if ( ! isset($param[$val]))
                                {
                                        $param[$val] = '';
                                }
                        }

                        ocibindbyname($this->stmt_id, $param['name'], $param['value'], $param['length'], $param['type']);
                }
        }

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

        /**
         * 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;
                
                $this->_commit = OCI_DEFAULT;
                return TRUE;
        }

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

        /**
         * 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;
                }

                $ret = OCIcommit($this->conn_id);
                $this->_commit = OCI_COMMIT_ON_SUCCESS;
                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;
                }

                $ret = OCIrollback($this->conn_id);
                $this->_commit = OCI_COMMIT_ON_SUCCESS;
                return $ret;
        }

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

        /**
         * Escape String
         *
         * @access  public
         * @param   string
         * @return  string
         */
        function escape_str($str)
        {
                // Access the CI object
                $CI =& get_instance();

                return $CI->_remove_invisible_characters($str);
        }

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

        /**
         * Affected Rows
         *
         * @access  public
         * @return  integer
         */
        function affected_rows()
        {
                return @ocirowcount($this->stmt_id);
        }

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

        /**
         * Insert ID
         *
         * @access  public
         * @return  integer
         */
        function insert_id()
        {
                // not supported in oracle
                return $this->display_error('db_unsupported_function');
        }

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

        /**
         * "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 == FALSE)
                        {
                        return 0;
                        }

                $row = $query->row();
                return $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 = "SELECT TABLE_NAME FROM ALL_TABLES";

                if ($prefix_limit !== FALSE AND $this->dbprefix != '')
                {
                        $sql .= " WHERE TABLE_NAME LIKE '".$this->dbprefix."%'";
                }
                
                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($table = '')
        {
                return "SELECT COLUMN_NAME FROM all_tab_columns WHERE table_name = '$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($table)
        {
                return "SELECT * FROM ".$table." where rownum = 1";
        }

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

        /**
         * The error message string
         *
         * @access  private
         * @return  string
         */
        function _error_message()
        {
                $error = ocierror($this->conn_id);
                return $error['message'];
        }

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

        /**
         * The error message number
         *
         * @access  private
         * @return  integer
         */
        function _error_number()
        {
                $error = ocierror($this->conn_id);
                return $error['code'];
        }
        
        // --------------------------------------------------------------------

        /**
         * 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;
                }
        
                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 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).")";
        }

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

        /**
         * 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;
        }

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

        /**
         * 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($table)
        {
                return "TRUNCATE TABLE ".$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)
        {
                $limit = $offset + $limit;
                $newsql = "SELECT * FROM (select inner_query.*, rownum rnum FROM ($sql) inner_query WHERE rownum < $limit)";

                if ($offset != 0)
                {
                        $newsql .= " WHERE rnum >= $offset";
                }

                // remember that we used limits
                $this->limit_used = TRUE;

                return $newsql;
        }       

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

        /**
         * Close DB Connection
         *
         * @access  public
         * @param   resource
         * @return  void
         */
        function _close($conn_id)
        {
                @ocilogoff($conn_id);
        }


}



/* End of file oci8_driver.php */
/* Location: ./system/database/drivers/oci8/oci8_driver.php */