public static function deleteTopicTags($topicId, $tagNames)
{
if ($oldTags = static::find(['id'])->where(['name' => $tagNames])->asArray()->all()) {
$tagIds = ArrayHelper::getColumn($oldTags, 'id');
TagTopic::deleteAll(['topic_id' => $topicId, 'tag_id' => $tagIds]);
static::updateAll(['updated_at' => time(), 'topic_count' => new Expression('`topic_count` - 1')], ['and', ['id' => $tagIds], ['>', 'topic_count', 0]]);
}
}
