I am new to SQL.I have two tables Customers and deposit_transactions. I am trying to select the country which has the highest account balance as of latest date. I am joining deposit_transactions table(to get the sum of amount based on customer_id) and joining with customers table to get the Country

Schema (MySQL v8.0)

CREATE TABLE deposit_transactions (
  `deposit_id` VARCHAR(7),
  `customer_id` VARCHAR(5),
  `date` TEXT,
  `transaction_type` VARCHAR(7),
  `amount` INTEGER,
  `currency` VARCHAR(3)
);

INSERT INTO deposit_transactions
  (`deposit_id`, `customer_id`, `date`, `transaction_type`, `amount`, `currency`)
VALUES
  ('DE47653', 'DO900', '1/1/2019', 'pay_in', '10000', 'EUR'),
  ('DE47654', 'DO901', '2/1/2019', 'pay_in', '10000', 'EUR'),
  ('DE47655', 'DO902', '2/1/2019', 'pay_in', '10000', 'EUR'),
  ('UK47656', 'DO903', '3/1/2019', 'pay_in', '10000', 'GBP'),
  ('UK47657', 'DO904', '3/1/2019', 'pay_in', '130000', 'GBP'),
  ('DE47658', 'DO905', '3/1/2019', 'pay_in', '140000', 'EUR'),
  ('DE47659', 'DO906', '3/1/2019', 'pay_in', '10000', 'EUR'),
  ('DE47660', 'DO907', '3/1/2019', 'pay_in', '10000', 'EUR'),
  ('DE47661', 'DO908', '3/1/2019', 'pay_in', '100000', 'EUR'),
  ('DE47662', 'DO909', '4/1/2019', 'pay_in', '10000', 'EUR'),
  ('UK47663', 'DO910', '4/1/2019', 'pay_in', '10000', 'GBP'),
  ('UK47664', 'DO911', '4/1/2019', 'pay_in', '5000', 'GBP'),
  ('UK47665', 'DO912', '4/1/2019', 'pay_in', '4000', 'GBP'),
  ('DE47666', 'DO913', '5/1/2019', 'pay_in', '10000', 'EUR'),
  ('DE47661', 'DO908', '5/1/2019', 'pay_out', '50000', 'EUR'),
  ('DE47667', 'DO914', '11/1/2019', 'pay_in', '30000', 'EUR'),
  ('DE47668', 'DO915', '11/1/2019', 'pay_in', '10000', 'EUR'),
  ('DE47669', 'DO916', '11/1/2019', 'pay_in', '25000', 'EUR'),
  ('DE47670', 'DO917', '11/1/2019', 'pay_in', '50000', 'EUR'),
  ('DE47667', 'DO914', '12/1/2019', 'pay_out', '7000', 'EUR'),
  ('DE47667', 'DO914', '12/15/2019', 'pay_in', '12000', 'EUR'),
  ('DE47671', 'DO918', '1/1/2021', 'pay_in', '9000', 'EUR'),
  ('DE47672', 'DO919', '1/1/2021', 'pay_in', '10000', 'EUR'),
  ('DE47673', 'DO920', '1/1/2021', 'pay_in', '11000', 'EUR'),
  ('DE47674', 'DO921', '1/1/2021', 'pay_in', '12000', 'EUR'),
  ('DE47675', 'DO922', '1/1/2021', 'pay_in', '13000', 'EUR'),
  ('DE47676', 'DO923', '1/1/2021', 'pay_in', '14000', 'EUR'),
  ('DE47677', 'DO924', '1/1/2021', 'pay_in', '30000', 'EUR'),
  ('DE47678', 'DO925', '1/1/2021', 'pay_in', '16000', 'EUR');

CREATE TABLE customers (
  `customer_id` VARCHAR(5),
  `country` VARCHAR(7)
);

INSERT INTO customers
  (`customer_id`, `country`)
VALUES
  ('DO900', 'Germany'),
  ('DO901', 'Germany'),
  ('DO902', 'Spain'),
  ('DO903', 'UK'),
  ('DO904', 'UK'),
  ('DO905', 'Austria'),
  ('DO906', 'Germany'),
  ('DO907', 'Germany'),
  ('DO908', 'Germany'),
  ('DO909', 'Germany'),
  ('DO910', 'UK'),
  ('DO911', 'UK'),
  ('DO912', 'UK'),
  ('DO913', 'Germany'),
  ('DO914', 'Austria'),
  ('DO915', 'Germany'),
  ('DO916', 'Austria'),
  ('DO917', 'Germany'),
  ('DO918', 'Germany'),
  ('DO919', 'Spain'),
  ('DO920', 'Germany'),
  ('DO921', 'Spain'),
  ('DO922', 'Germany'),
  ('DO923', 'Germany'),
  ('DO924', 'Germany'),
  ('DO925', 'Spain'),
  ('DO926', 'Germany'),
  ('DO927', 'Germany'),
  ('DO928', 'Germany'),
  ('DO929', 'Germany'),
  ('DO711', 'UK'),
  ('DO712', 'UK'),
  ('DO713', 'Germany'),
  ('DO714', 'Austria'),
  ('DO715', 'Germany'),
  ('DO716', 'Austria'),
  ('DO717', 'Germany'),
  ('DO718', 'Germany'),
  ('DO719', 'Spain'),
  ('DO720', 'Germany'),
  ('DO721', 'Spain'),
  ('DO722', 'Germany'),
  ('DO723', 'Germany'),
  ('DO724', 'Germany'),
  ('DO725', 'Spain'),
  ('DO726', 'Germany'),
  ('DO727', 'Germany'),
  ('DO728', 'Germany'),
  ('DO729', 'Germany');

Below is the sample query I created. But I am not sure if its correct

Query

SELECT t.customer_id,
       c.country,t.total_amount
FROM  (SELECT customer_id,
              date,
              transaction_type,
              Sum(amount)
                OVER (
                  partition BY customer_id ) AS total_amount_transfered,
              Row_number()
                OVER (
                  partition BY customer_id
                  ORDER BY date DESC)        AS n
       FROM   deposit_transactions)t
      INNER JOIN customers AS c
              ON c.customer_id = t.customer_id
WHERE  t.n = 1
       AND t.transaction_type="pay_in" order by total_amount desc limit 1;