在 Yii2 中，使用关联查询时，报错：yii\base\ErrorException: Undefined index: id in \vendor\yiisoft\yii2\db\ActiveRelationTrait.php:554

1、在 Yii2 中，使用关联查询时，报错：yii\base\ErrorException: Undefined index: id in \vendor\yiisoft\yii2\db\ActiveRelationTrait.php:554。如图1

图1

$query = ConventionFreeRegistration::find()
	->select(ConventionFreeRegistration::tableName() . '.audit_state, COUNT(' . ConventionFreeRegistration::tableName() . '.`id`) AS `count`')
	->where([
		ConventionFreeRegistration::tableName() . '.convention_id' => $conventionId,
	])
	->groupBy(ConventionFreeRegistration::tableName() . '.audit_state')
	->indexBy(ConventionFreeRegistration::tableName() . '.audit_state');

$count = $query
	->joinWith(['distributor'])
	->andWhere([ConventionDistributor::tableName() . '.user_id' => Yii::$app->user->id])
	->asArray()
	->all();

// 在模型 ConventionFreeRegistration 定义关联
    public function getDistributor() {
        return $this->hasOne(ConventionDistributor::class, ['convention_id' => 'convention_id', 'id' => 'distributor_id'])
        ->viaTable(ConventionRegistrationDistributorMapping::tableName(), ['registration_id' => 'id', 'convention_id' => 'convention_id']);
    }

2、确认生成的 SQL 执行时，不会报错。如图2

图2

3、调整代码实现，删除掉 ->asArray()，不再报错。但是，这样的话，无法获取到 count 的值。使用更可靠的替代方案，使用 leftJoin，不再报错。如图3

图3

$query = ConventionFreeRegistration::find()
	->select('t.audit_state, COUNT(t.`id`) AS `count`')
	->from(ConventionFreeRegistration::tableName() . ' t')
	->where([
		't.convention_id' => $conventionId,
	])
	->groupBy('t.audit_state')
	->indexBy('t.audit_state');

$count = $query
	->leftJoin(
		ConventionRegistrationDistributorMapping::tableName() . ' m',
		't.id = m.registration_id AND t.convention_id = m.convention_id'
	)
	->leftJoin(
		ConventionDistributor::tableName() . ' d',
		'm.convention_id = d.convention_id AND m.distributor_id = d.id'
	)
	->andWhere(['d.user_id' => Yii::$app->user->id])
	->asArray()
	->all();