クラス yii\db\Transaction

                public function begin($isolationLevel = null)
{
    if ($this->db === null) {
        throw new InvalidConfigException('Transaction::db must be set.');
    }
    $this->db->open();
    if ($this->_level === 0) {
        if ($isolationLevel !== null) {
            $this->db->getSchema()->setTransactionIsolationLevel($isolationLevel);
        }
        Yii::debug('Begin transaction' . ($isolationLevel ? ' with isolation level ' . $isolationLevel : ''), __METHOD__);
        $this->db->trigger(Connection::EVENT_BEGIN_TRANSACTION);
        $this->db->pdo->beginTransaction();
        $this->_level = 1;
        return;
    }
    $schema = $this->db->getSchema();
    if ($schema->supportsSavepoint()) {
        Yii::debug('Set savepoint ' . $this->_level, __METHOD__);
        // make sure the transaction wasn't autocommitted
        if ($this->db->pdo->inTransaction()) {
            $schema->createSavepoint('LEVEL' . $this->_level);
        }
    } else {
        Yii::info('Transaction not started: nested transaction not supported', __METHOD__);
        throw new NotSupportedException('Transaction not started: nested transaction not supported.');
    }
    $this->_level++;
}

            

                public function commit()
{
    if (!$this->getIsActive()) {
        throw new Exception('Failed to commit transaction: transaction was inactive.');
    }
    $this->_level--;
    if ($this->_level === 0) {
        Yii::debug('Commit transaction', __METHOD__);
        // make sure the transaction wasn't autocommitted
        if ($this->db->pdo->inTransaction()) {
            $this->db->pdo->commit();
        }
        $this->db->trigger(Connection::EVENT_COMMIT_TRANSACTION);
        return;
    }
    $schema = $this->db->getSchema();
    if ($schema->supportsSavepoint()) {
        Yii::debug('Release savepoint ' . $this->_level, __METHOD__);
        // make sure the transaction wasn't autocommitted
        if ($this->db->pdo->inTransaction()) {
            $schema->releaseSavepoint('LEVEL' . $this->_level);
        }
    } else {
        Yii::info('Transaction not committed: nested transaction not supported', __METHOD__);
    }
}

            

                public function getIsActive()
{
    return $this->_level > 0 && $this->db && $this->db->isActive;
}

            

                public function getLevel()
{
    return $this->_level;
}

            

                public function rollBack()
{
    if (!$this->getIsActive()) {
        // do nothing if transaction is not active: this could be the transaction is committed
        // but the event handler to "commitTransaction" throw an exception
        return;
    }
    $this->_level--;
    if ($this->_level === 0) {
        Yii::debug('Roll back transaction', __METHOD__);
        // make sure the transaction wasn't autocommitted
        if ($this->db->pdo->inTransaction()) {
            $this->db->pdo->rollBack();
        }
        $this->db->trigger(Connection::EVENT_ROLLBACK_TRANSACTION);
        return;
    }
    $schema = $this->db->getSchema();
    if ($schema->supportsSavepoint()) {
        Yii::debug('Roll back to savepoint ' . $this->_level, __METHOD__);
        // make sure the transaction wasn't autocommitted
        if ($this->db->pdo->inTransaction()) {
            $schema->rollBackSavepoint('LEVEL' . $this->_level);
        }
    } else {
        Yii::info('Transaction not rolled back: nested transaction not supported', __METHOD__);
    }
}

            

                public function setIsolationLevel($level)
{
    if (!$this->getIsActive()) {
        throw new Exception('Failed to set isolation level: transaction was inactive.');
    }
    Yii::debug('Setting transaction isolation level to ' . $level, __METHOD__);
    $this->db->getSchema()->setTransactionIsolationLevel($level);
}