ROUND

1
SELECT
2
  ROUND(3.14159) as default_round,
3
  ROUND(3.14159, 2) as two_decimal,
4
  ROUND(3.14159, 4) as four_decimal;

1
SELECT
2
  ROUND(1234, -1) as to_tens,
3
  ROUND(1234, -2) as to_hundreds,
4
  ROUND(1234, -3) as to_thousands;

1
SELECT
2
  category,
3
  COUNT(*) as count,
4
  ROUND(COUNT(*) * 100.0 / SUM(COUNT(*)) OVER (), 2) as percentage
5
FROM orders
6
GROUP BY category;

1
SELECT
2
  product_name,
3
  price,
4
  ROUND(price, -2) as rounded_price
5
FROM products;