yii中将log存入数据库是修改原有风格

YII是提供修改输出参数格式的，但是可供用户定制化的空间非常小。

如想把prefix中的userID和ip分别插入到数据库中不同的两列，就需要需改框架文件：

/basic/vendor/yiisoft/yii2/log/Target与/basic/vendor/yiisoft/yii2/log/DbTarget如下：

    public function getMessagePrefixCustomized($message)
    {
        if ($this->prefix !== null) {
            return call_user_func($this->prefix, $message);
        }

        if (Yii::$app === null) {
            return '';
        }

        $request = Yii::$app->getRequest();
        $ip = $request instanceof Request ? $request->getUserIP() : '-';

        /* @var $user yiiwebUser */
        $user = Yii::$app->has('user', true) ? Yii::$app->get('user') : null;
        if ($user && ($identity = $user->getIdentity(false))) {
            $userID = $identity->getId();
        } else {
            $userID = '-';
        }

        /* @var $session yiiwebSession */
        $session = Yii::$app->has('session', true) ? Yii::$app->get('session') : null;
        $sessionID = $session && $session->getIsActive() ? $session->getId() : '-';

        $results = array('ip' => $ip, 'userID' => $userID, 'sessionID' => $sessionID);
           //return "[$ip][$userID][$sessionID]";
        return $results;//原来是返回一个string这里返回一个数组
    }

    public function export()
    {
        $tableName = $this->db->quoteTableName($this->logTable);
        $sql = "INSERT INTO $tableName ([[level]], [[category]], [[log_time]], [[message]], [[IP]], [[customerID]])
                VALUES (:level, :category, :log_time, :message, :IP, :customerID)";//在这里修改在数据库中要显示的字段
        $command = $this->db->createCommand($sql);
        foreach ($this->messages as $message) {
            list($text, $level, $category, $timestamp) = $message;
            if (!is_string($text)) {
                $text = VarDumper::export($text);
            }
            $command->bindValues([
                ':level' => $level,
                ':category' => $category,
                ':log_time' => date('Y-m-d H:i:s'),//如需修改时间戳格式在这里修改
                ':customerID' => $this->getMessagePrefixCustomized($message)['userID'],//从上边的函数里边的返回值
                ':IP' => $this->getMessagePrefixCustomized($message)['ip'],
                ':message' => $text,
            ])->execute();
        }
    }