SQL syntax error inside CAST with case statement

I want to list positive and negative bank_transfers from my DB. To do so I’m using below query:

SELECT
  bank_transfers.date AS day,
  CAST(SUM(CASE WHEN bank_transfers.amount_cents < 0 THEN bank_transfers.amount_cents END)) AS sum_expenses,
  CAST(SUM(CASE WHEN bank_transfers.amount_cents > 0 THEN bank_transfers.amount_cents END)) AS sum_revenue
FROM bank_transfers
JOIN customers ON customers.id = bank_transfers.customer_id
WHERE customers.id = 1
AND bank_transfers.date < '2020-11-26'
AND bank_transfers.date >= '2020-08-26'
GROUP BY DAY

But it gives me an error syntax error at or near ")". I guess it comes from the CAST so where should I close the parentheses?

Answer

You don’t even need those casts. You’re not casting into any type (unless sum_expenses and sum_revenue are your custom types).

Edit: If you want to cast to integer:

SELECT
  bank_transfers.date AS day,
  SUM(CASE WHEN bank_transfers.amount_cents < 0 THEN bank_transfers.amount_cents END)::integer AS sum_expenses,
  SUM(CASE WHEN bank_transfers.amount_cents > 0 THEN bank_transfers.amount_cents END)::integer AS sum_revenue
FROM bank_transfers
JOIN customers ON customers.id = bank_transfers.customer_id
WHERE customers.id = 1
AND bank_transfers.date < '2020-11-26'
AND bank_transfers.date >= '2020-08-26'
GROUP BY DAY

Or use cast(... as integer).