Think/Db/Driver.php
public function rollback()
    {
        if ($this->transTimes > 0) {
            $result = $this->_linkID->rollBack();
            $this->transTimes = 0;
            if (!$result) {
                $this->error();

                return false;
            }
        }

        return true;
    }
public function rollback()
    {
        if ($this->transTimes > 0) {
            $result = $this->_linkID->rollBack();
            $this->transTimes = 0;
            if (!$result) {
                $this->error();

                return false;
            }
        }

        return true;
    }
事务回滚

@return bool