各位前輩好

目前想設計一個資料庫，負責帳號的管理
大概像這樣：

table: account
id | account | parent_account | account_level
 1 |   aa123 |           boss |             1
 2 |    boss |        bigboss |             2
 3 | bigboss |           null |             3
 4 |   bb123 |           boss |             1

account_level 數字越大階級越高
parent_account 紀錄他的主管帳號
所以以上表來看，階級關係會是： bigboss > boss > aa123

另外有一張table是用來放一些工作紀錄

table: record
id | account | whatyouneedtodo
 1 |   aa123 |            work
 2 |   aa123 |        workhard
 3 |    boss |           sleep
 4 | bigboss |       donothing
 5 |   bb123 |            work

接著會依登入的帳號，列出登入者自己和他底下所有員工的工作紀錄

例(1) 登入aa123，列出
id | account | whatyouneedtodo
 1 |   aa123 |            work
 2 |   aa123 |        workhard

例(2) 登入boss，列出
id | account | whatyouneedtodo
 1 |   aa123 |            work
 2 |   aa123 |        workhard
 3 |    boss |           sleep
 5 |   bb123 |            work

例(1) 登入bigboss，列出
id | account | whatyouneedtodo
 1 |   aa123 |            work
 2 |   aa123 |        workhard
 3 |    boss |           sleep
 4 | bigboss |       donothing
 5 |   bb123 |            work

Q: 目前卡在SQL語法不知道怎麼下會更好
假設變數loginAccount代表登入的帳號

這樣可以顯示階級1的資料
SELECT * FROM record WHERE account = loginAccount

這樣可以顯示階級2的資料
SELECT * 
FROM record 
WHERE account = loginAccount or account IN (
    SELECT account 
    FROM account 
    WHERE parent_account = loginAccount)

這樣可以顯示階級3的資料
SELECT 
    *
FROM
    record
WHERE
    account = loginAccount
        OR account IN (SELECT 
            account
        FROM
            account
        WHERE
            parent_account = loginAccount)
        OR account IN (SELECT 
            account
        FROM
            account
        WHERE
            parent_account IN (SELECT 
                    account
                FROM
                    account
                WHERE
                    parent_account = loginAccount))

不知道有沒有更好的SQL下法？想請前輩指點
或是將table更改成什麼樣子，會更好下SQL

希望可以做到日後如果再加一個account_level
也不會有太大幅度的更動

想請各位前輩指點一下，或是table能怎麼更改會更好查詢
謝謝！

補上資料庫

CREATE TABLE `account` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `account` varchar(45) DEFAULT NULL,
  `parent_account` varchar(45) DEFAULT NULL,
  `account_level` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;

LOCK TABLES `account` WRITE;
INSERT INTO `account` VALUES (1,'aa123','boss','1'),(2,'boss','bigboss','2'),(3,'bigboss',NULL,'3'),(4,'bb123','boss','1');
UNLOCK TABLES;

CREATE TABLE `record` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `account` varchar(45) DEFAULT NULL,
  `whatyouneedtodo` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=latin1;

LOCK TABLES `record` WRITE;
INSERT INTO `record` VALUES (1,'aa123','work'),(2,'aa123','workhard'),(3,'boss','sleep'),(4,'bigboss','donothing'),(5,'bb123','work');
UNLOCK TABLES;