Yii1. Internationalization (I18N) using DB.

Create the following tables:

CREATE TABLE SourceMessage
(
    id INTEGER PRIMARY KEY,
    category VARCHAR(32),
    message TEXT
);
CREATE TABLE Message
(
    id INTEGER,
    language VARCHAR(16),
    translation TEXT,
    PRIMARY KEY (id, language),
    CONSTRAINT FK_Message_SourceMessage FOREIGN KEY (id)
         REFERENCES SourceMessage (id) ON DELETE CASCADE ON UPDATE RESTRICT
);

INSERT INTO `SourceMessage` (`id`, `category`, `message`) VALUES
(1, 'foo', 'Hello');

INSERT INTO `Message` (`id`, `language`, `translation`) VALUES
(1, 'es', 'Hola');

Put component into the main config:

'components' => array(
        ...
        'messages'=>array(
            'class'=>'CDbMessageSource'
        ),
        ...
)

Use it everywhere:

class FooController extends CController {
    
    function actionBar() {
        
        Yii::app()->setLanguage('es');
        
        echo Yii::t('foo', 'Hello'); die; // will output 'Hola'
    }
}