Navigation:  Development > MVC (Model View Controller) > Model > Installer

A model can have a installer class to execute query. installer contain a batch of query that execute on each version update of a mode. All installers we create in "installer" directory inside the folder of model.
 
Installer is a class that extends model class and name of the class follow the folder path of it. See below example
 
Model Class:
First create the model class with a latest version
 
class blogCommentModel extends appRain_Base_Model
{
   public $version = "0.1.0";
   public $name = "BlogComment";
   public $db_table = "blogcomments";
   public $relation = array();
   protected $model_validation = Array();
}
 
Installer Class:
Create installer class that extends model. The installer class has a method installerResource() that return query. System always execute query for present version of model. To create a SQL batch we update model version then create new SQL batch in return array.
 
Version number in model must sequentially incremental. For example: 0.1.0, 0.1.2 ....0.1.9,2.0.1,2.0.2 etc.

 

 
class Development_Models_Installer_blogComment extends blogCommentModel
{
 
   public function installerResource()
   {
      $prefix =  App::get("db_prefix");

 
      return array(
          "0.1.0"=>"CREATE TABLE IF NOT EXISTS `{$prefix['primary']}blogcomments` (
               `id` int(11) NOT NULL AUTO_INCREMENT,
               `postid` int(11) NOT NULL,
               `userid` int(11) NOT NULL,
               `name` varchar(100) NOT NULL,
               `email` varchar(100) NOT NULL,
               `website` varchar(100) NOT NULL,
               `comment` text NOT NULL,
               `dated` datetime NOT NULL,
               `status` enum('Active','Inactive') NOT NULL,
               PRIMARY KEY (`id`)
           ) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;"
       );
   }
}

 

Troubleshooting:

 

1.Check Model Version and Installer index. You can also check model version form below location:

a.Login Admin Panel and Click Preferences.

b.On left Side click on System > MVC Manager and check version of model.

2.Set Model Version Control=Yes in System Configuration from below location:
Admin Panel > Preferences > Configuration

3.Set Debug=2 from below location to see the system SQL list at below of the page:
Admin Panel > Preferences > Configuration

4.For further inspection you can see the updated version in database table coreresources