无法在Yii中的连接表中插入记录

Question

I'm new to Yii2. I've three tables project, amenity and a junction table project_amenity, and here is the code:

Project Model:

<?php
namespace app\models;
use yii\db\ActiveRecord;

class Project extends \yii\db\ActiveRecord
{
    public function getAmenities()
    {
        return $this->hasMany(Amenity::className(), ['id' => 'amenity_id'])->viaTable('project_amenity', ['project_id' => 'id']);
    }

    public function rules()
    {
        return [
            [['name', 'city'], 'required'],
        ];
    }
}

Amenity Model:

<?php
namespace app\models;
use yii\db\ActiveRecord;

class Amenity extends \yii\db\ActiveRecord
{
    public function getProjects()
    {
        return $this->hasMany(Project::className(), ['id' => 'project_id'])->viaTable('project_amenity', ['amenity_id' => 'id']);
    }
}

ProjectController:

<?php

namespace app\controllers;

use Yii;
use yii\filters\AccessControl;
use yii\web\Controller;
use app\models\Project;
use app\models\Amenity;
use yii\helpers\ArrayHelper;
class ProjectController extends Controller
{
    public function actionCreate()
    {
        $project = new Project;
        $amenities = ArrayHelper::map(Amenity::find()->all(), 'id', 'name');

        if ($project->load(Yii::$app->request->post()) && $project->save()) {
            return $this->render(['confirm', 'id' => $project->id]);
        } else {
            return $this->render('create', [
                'project' => $project, 'amenities' => $amenities
            ]);
        }
    }
}

And here is the Incomplete create view:

<?php
use yii\helpers\Html;
use yii\widgets\LinkPager;
use yii\widgets\ActiveForm;

?>
<?php $form = ActiveForm::begin(); ?>
    <table class="table">
        <tr>
            <td><?= $form->field($project, 'name'); ?></td>
        </tr>
        <tr>
            <td ><?= $form->field($project, 'city'); ?></td>
        </tr>
        <tr>
            <td><?= Html::submitButton('Submit', ['class' => 'btn btn-primary']) ?></td>
        </tr>
    </table>

<?php ActiveForm::end(); ?>

ProjectAmenity Junction Model

<?php
namespace app\models;
use yii\db\ActiveRecord;

class ProjectAmenity extends \yii\db\ActiveRecord
{
    public static function tableName()
    {
        return 'project_amenity';
    }
    public function rules()
    {
        return [
            [['project_id', 'amenity_id'], 'required']
        ];
    }
}
?>

I'am able to display the relational data but not able to insert. Please suggest how to display the amenity checkboxes on create view and and how to insert the data in project and project_amenity table from the create view.

Answer 1

Add amenities property to your project model:

public $amenities;

Add a checkboxlist to your view:

<?= $form->field($project, 'amenities')->checkboxList($amenities) ?>

Create junction model if not already exists.

Loop through input in create action after save:

if ($project->load(Yii::$app->request->post()) && $project->save()) {
    // checkboxlist fills amenities property with corresponding keys
    foreach($project->amenities as $amenity_key) {
        $project_amenity = new ProjectAmenity([
            'project_id' => $project->id,
            'amenity_id' => $amenity_key
        ]);
        $project_amenity->save();
    }
}