Prevent lost updates with high transaction isolation levels: Is this a common misconception?-CodePudding

I noticed that my applications often write values to a database that depend on a former read operation. A common example is a bank account where a user could deposit money:

void deposit(amount) {
    balance = getAccountBalance()
    setAccountBalance(balance   amount)
}

I want to avoid a race condition if this method is called by two threads/clients/ATMs simultaneously like this where the account owner would lose money:

balance = getAccountBalance()       |
                                    | balance = getAccountBalance()
setAccountBalance(balance   amount) |
                                    | // balance2 = getAccountBalance() // theoretical
                                    | setAccountBalance(balance   amount)
                                    V

I often read that Repeatable Read or Serializable can solve this problem. Even the

Sorry it is in franch, but I think it is readable...