Code reviewHardcr-g639

Subject Transaction isolationLevel Mid–Senior~25 minCommon in Databases & SQL interviewsIndustries Software development

Question

Review this Go function that deducts from a wallet balance.

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Code to reviewgo

1func Withdraw(ctx context.Context, db *sql.DB, userID int64, amount int64) error {2    var balance int643    err := db.QueryRowContext(ctx,4        "SELECT balance FROM wallets WHERE user_id = $1", userID).Scan(&balance)5    if err != nil {6        return err7    }8    if balance < amount {9        return ErrInsufficientFunds10    }11    _, err = db.ExecContext(ctx,12        "UPDATE wallets SET balance = $1 WHERE user_id = $2", balance-amount, userID)13    return err14}

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