invoice.sql

-- 1: Count how many orders were made from the USA.

SELECT COUNT(*) FROM invoice
WHERE billing_country = 'USA';

-- 2: Find the largest order total amount.

SELECT total FROM invoice
ORDER BY total DESC
LIMIT 1;

-- 3: Find the smallest order total amount.

SELECT total FROM invoice
ORDER BY total ASC
LIMIT 1;

-- 4: Find all orders bigger than $5.

SELECT * FROM invoice
WHERE total > 5;

-- 5: Count how many orders were smaller than $5.

SELECT COUNT(*) FROM invoice
WHERE total < 5;

-- 6: Count how many orders were in CA, TX, or AZ (use IN).

SELECT billing_state, COUNT(*) FROM invoice
WHERE billing_state  IN ('CA', 'TX', 'AZ')
GROUP BY billing_state;

-- 7: Get the average total of the orders.

SELECT AVG(total) FROM invoice;

-- 8: Get the total sum of the orders.

SELECT SUM(total) FROM invoice;

-- 9: Update the invoice with an invoice_id of 5 to have a total order amount of 24.

UPDATE invoice
SET total = 24
WHERE invoice_id = 5;

-- 10: Delete the invoice with an invoice_id of 1.

DELETE FROM invoice
WHERE invoice_id = 1;