Active Record parallel queries

Category:Core | Category:Core::Database | Category:Core::Community

This is a replacement of the [b]system/database/DB_active_rec.php[/b] file, allowing you to use several CI Active Record threads at the same time without overlapping. See the relevant [url=http://codeigniter.com/forums/viewthread/54113/]forum thread[/url].

Sample code: [code]$this->db->set_identifier('my_first_query'); $this->db->from('blabla'); $this->db->where('blibli');

$this->db->set_identifier('my_second_query'); $this->db->from('tatata'); $this->db->where('tititi');

$this->db->set_identifier('my_first_query'); $first_query = $this->db->get();

$this->db->set_identifier('my_second_query'); $second_query = $this->db->get();[/code]

It's fully backward compatible, and you could use it also this way (adding two lines around the code to protect from other AR calls):

[code]$this->db->set_identifier("my unique string that I won't use twice unless it's really clean"); $query = $this->db->getwhere('a_table', array('id' => $id)); $result = $query->first_row(); $this->db->set_identifier('default');[/code]

Some apps (like Rapyd in dataset.php around line 253) tweak some AR variables without using the public functions. You'll have to hack them if you want to use the new [b]DB_active_rec.php[/b]. For example in Rapyd, the lines

[code]// ... $this->db->ar_limit = FALSE; // ... $this->db->ar_select = array('COUNT(*) AS totalrows');
// ... $this->db->ar_orderby = array(); // ... $this->db->ar_order = FALSE;[/code]

becomes

[code]// ... $this->db->ar_limit['default'] = FALSE; // ... $this->db->ar_select['default'] = array('COUNT(*) AS totalrows');
// ... $this->db->ar_orderby['default'] = array(); // ... $this->db->ar_order['default'] = FALSE;[/code]

Here is a piece of the code of this new file.

[code]<?php /**

• Active Record Class

• This is the platform-independent base Active Record implementation class.

• Changes by Christophe Gragnic on 2007/06/14 are:

•     vars now arrays of old vars
  

•     added var $ar_identifier and its setter
  

•     everywhere you had $this->ar_somevar, you now have
  

•     $this->ar_somevar[$this->ar_identifier]
  

• Those changes allow us to use Active Record parallel queries.

• The "identifier" is a simple string (default:'default').

• Backward compatible, set_identifier('some_identifier') is optional.

• Sample code:

• $this->db->set_identifier('my_first_query');

• $this->db->from('blabla');

• $this->db->where('blibli');

• $this->db->set_identifier('my_second_query');

• $this->db->from('tatata');

• $this->db->where('tititi');

• $this->db->set_identifier('my_first_query');

• $first_query = $this->db->get();

• $this->db->set_identifier('my_second_query');

• $second_query = $this->db->get();

• @package CodeIgniter

• @subpackage Drivers

• @category Database

• @author Rick Ellis

• @author Christophe Gragnic (grahack) for the identifier stuff only

• @link http://www.codeigniter.com/user_guide/database/ */ class CI_DB_active_record extends CI_DB_driver {

  var $ar_identifier = 'default';

  var $ar_select = array('default' => array()); var $ar_distinct = array('default' => FALSE); var $ar_from = array('default' => array()); var $ar_join = array('default' => array()); var $ar_where = array('default' => array()); var $ar_like = array('default' => array()); var $ar_groupby = array('default' => array()); var $ar_having = array('default' => array()); var $ar_limit = array('default' => FALSE); var $ar_offset = array('default' => FALSE); var $ar_order = array('default' => FALSE); var $ar_orderby = array('default' => array()); var $ar_set = array('default' => array());

  /**

  • Set_identifier

  • Chooses the channel to use

  • @access public

  • @param string

  • @return object */ function set_identifier($identifier = 'default') { if ( ! is_string($identifier)) { $identifier = 'default'; }

    $this->ar_identifier = $identifier;

    // we have to init the values only if it is a new key // let's check on the first array if ( ! array_key_exists($identifier, $this->ar_select)) { $this->ar_select [$identifier] = array(); $this->ar_distinct [$identifier] = FALSE; $this->ar_from [$identifier] = array(); $this->ar_join [$identifier] = array(); $this->ar_where [$identifier] = array(); $this->ar_like [$identifier] = array(); $this->ar_groupby [$identifier] = array(); $this->ar_having [$identifier] = array(); $this->ar_limit [$identifier] = FALSE; $this->ar_offset [$identifier] = FALSE; $this->ar_order [$identifier] = FALSE; $this->ar_orderby [$identifier] = array(); $this->ar_set [$identifier] = array(); } return $this; }[/code]

[h3]Download[/h3] File:DB_active_rec.zip