Yii2返回以主键id为键名的数组

<?php

namespace app\models;

use Yii;

/**
 * This is the model class for table "branch".
 *
 * @property integer $id
 * @property string $name
 *
 */
class Branch extends \yii\db\ActiveRecord
{
    /**
     * @inheritdoc
     */
    public static function tableName()
    {
        return ‘branch‘;
    }

    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [[‘name‘], ‘string‘, ‘max‘ => 45],
        ];
    }

    /**
     * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
            ‘id‘ => ‘ID‘,
            ‘name‘ => ‘Name‘,
        ];
    }
　　public static function getKeyValuePairs()
    {
        $sql = ‘SELECT id, name FROM ‘ . self::tableName() . ‘ ORDER BY name ASC‘;
    
        return Yii::$app->db->createCommand($sql)->queryAll(\PDO::FETCH_KEY_PAIR);
    }
}

<?php

use yii\helpers\Html;
use yii\widgets\ActiveForm;
use app\models\Branch;
/* @var $this yii\web\View */
/* @var $model app\models\Pos */
/* @var $form yii\widgets\ActiveForm */
?>

<div class="pos-form">

    <?php $form = ActiveForm::begin(); ?>

    <?= $form->field($model, ‘serial‘)->textInput([‘maxlength‘ => true]) ?>
    <?= $form->field($model, ‘branch_id‘)->dropDownList(Branch::getKeyValuePairs())  ?>
    
    <?= $form->field($model, ‘is_enable‘)->checkBox() ?>

    <div class="form-group">
        <?= Html::submitButton($model->isNewRecord ? ‘Create‘ : ‘Update‘, [‘class‘ => $model->isNewRecord ? ‘btn btn-success‘ : ‘btn btn-primary‘]) ?>
    </div>

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

</div>