Customizing the ActiveQuery class

By default, all Active Record queries are supported by yii\db\ActiveQuery. To use a customized query class in an Active Record class, you should override the yii\db\ActiveRecord::find() method and return an instance of your customized query class.

Getting ready

1. Create a new application using the Composer package manager, as described in the official guide at http://www.yiiframework.com/doc-2.0/guide-start-installation.html.
2. Set up the database connection and create a table named post, as follows:

   DROP TABLE IF EXISTS 'post';
   CREATE TABLE IF NOT EXISTS 'post' (
       'id' INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
       'lang' VARCHAR(5) NOT NULL DEFAULT 'en',
       'title' VARCHAR(255) NOT NULL,
       'text' TEXT NOT NULL,
        PRIMARY KEY ('id')
   );
   INSERT INTO 'post'('id','lang','title','text')
   VALUES (1,'en_us','Yii news...