Displaying, sorting and filtering HasMany & ManyMany relations in CGridView

Tutorials

CGridView, sorting, filtering, has_many, many_many, gridview

---------

### 2.1 UseCase One - Lazy Loading

**Files/Methods**
- [models/Review::searchOne()](https://github.com/yjeroen/ManyMany/blob/master/protected/models/Review.php#L57) - [controllers/ReviewController::actionCaseOne()](https://github.com/yjeroen/ManyMany/blob/master/protected/controllers/ReviewController.php#L10) - [views/review/caseOne](https://github.com/yjeroen/ManyMany/blob/master/protected/views/review/caseOne.php#L1) - [views/review/_caseOneGrid](https://github.com/yjeroen/ManyMany/blob/master/protected/views/review/_caseOneGrid.php#L1)

**Explanation****Files/Methods**
- [models/Review::searchTwo()](https://github.com/yjeroen/ManyMany/blob/master/protected/models/Review.php#L130)   - [controllers/ReviewController::actionCaseTwo()](https://github.com/yjeroen/ManyMany/blob/master/protected/controllers/ReviewController.php#L54)   - [views/review/caseTwo](https://github.com/yjeroen/ManyMany/blob/master/protected/views/review/caseTwo.php#L1)   - [views/review/_caseTwoGrid](https://github.com/yjeroen/ManyMany/blob/master/protected/views/review/_caseTwoGrid.php#L1)  

**Explanation**You set a `$criteria->select`, that selects a GROUP_CONCAT of the data from Genre. Don't forget to set the attributes of the main Model here or else those aren't loaded. Note that you don't have to include the primary keys in this select statement. Those are automatically added by Yii.

A slight disadvantage about this method is that you can't use the loaded related data in your app like `$reviewModel->genres->name`, because the data is loaded in the class property `Review::$allGenres.
 
 
An example:

```php**Files/Methods**
- [extensions/classMap/CActiveFinder](https://github.com/yjeroen/ManyMany/blob/master/protected/extensions/classMap/CActiveFinder.php#L2) - [/index.php](https://github.com/yjeroen/ManyMany/blob/master/index.php#L29) - [models/Review::searchThree()](https://github.com/yjeroen/ManyMany/blob/master/protected/models/Review.php#L193) - [controllers/ReviewController::actionCaseThree()](https://github.com/yjeroen/ManyMany/blob/master/protected/controllers/ReviewController.php#L91) - [views/review/caseThree](https://github.com/yjeroen/ManyMany/blob/master/protected/views/review/caseThree.php#L1) - [views/review/_caseThreeGrid](https://github.com/yjeroen/ManyMany/blob/master/protected/views/review/_caseThreeGrid.php#L1)

**Explanation**4. $criteria->together has been set to true

_Note: I didn't test this custom CActiveFinder as much as the KeenLoading extension. I don't recommend using this usecase._

### 2.4 UseCase Four - KeenLoading**Files/Methods**
- [components/KeenActiveDataProvider](https://github.com/yjeroen/ManyMany/blob/master/protected/components/KeenActiveDataProvider.php)
- [models/Song::search()](https://github.com/yjeroen/ManyMany/blob/master/protected/models/Song.php#L81) - [controllers/SongController::actionSongs()](https://github.com/yjeroen/ManyMany/blob/master/protected/controllers/SongController.php#L50) - [controllers/SongController::setSearchInputs()](https://github.com/yjeroen/ManyMany/blob/master/protected/controllers/SongController.php#L7) - [views/song/songsGrid](https://github.com/yjeroen/ManyMany/blob/master/protected/views/song/songsGrid.php#L1) - [views/song/_songsGrid](https://github.com/yjeroen/ManyMany/blob/master/protected/views/song/_songsGrid.php#L1)

**Explanation**
Related data is loaded in a keen fashion. Using KeenActiveDataProvider, the related models are loaded in a separate query and then put into the relation properties of the earlier loaded models.

In your Models search function, you return a new KeenActiveDataProvider, instead of a CActiveDataProvider. The KeenActiveDataProvider has another option named 'withKeenLoading', where you can set the relations that you want to load in a second(or multiple) queries.