yii2 默认启动事务

背景：yii2事务的应用，需要配置事务的同事，还需要手动开启事务才能有效，但一些逻辑谨慎的平台需要默认开启事务。不手动执行commit就不能执行，这就需要手动更改动yii2框架代码了。

//开启事务
 $transaction = Yii::$app->getDb()->beginTransaction(); //如果注释掉整个事务，依旧可以执行
 $user = TdUser::findOne(62);
 $user->save();
 $transaction->commit(); //如果注释掉整个事务，依旧可以执行

更新文件：**/db/Connection.php ,大概在715行,手动添加一段代码。

public function createCommand($sql = null, $params = [])
    {

        //默认全局启动事务  private edit
        $transaction = $this->getTransaction();
        if(!$transaction){
            $transaction = $this->beginTransaction();
        }
        //end private edit

        $driver = $this->getDriverName();
        $config = ['class' => 'yii\db\Command'];
        if ($this->commandClass !== $config['class']) {
            $config['class'] = $this->commandClass;
        } elseif (isset($this->commandMap[$driver])) {
            $config = !is_array($this->commandMap[$driver]) ? ['class' => $this->commandMap[$driver]] : $this->commandMap[$driver];
        }
        $config['db'] = $this;
        $config['sql'] = $sql;
        /** @var Command $command */
        $command = Yii::createObject($config);
        return $command->bindValues($params);
    }