'How-to-code-summary-queries.sql' updaten

How-to-code-summary-queries.sql

@@ -1,14 +1,33 @@
 -- Exercise 1
-
+SELECT COUNT(order_id) AS order_count, SUM(tax_amount) AS tax_total
+FROM orders
 
 -- Exercise 2
-
+SELECT category_name, COUNT(product_id) AS product_count, MAX(list_price) AS most_expensive_product
+FROM categories c JOIN products p
+ON c.category_id = p.category_id
+GROUP BY category_name
+ORDER BY category_name DESC
 
 -- Exercise 3
-
+SELECT c.email_address, SUM(item_price) * quantity AS item_price_total, SUM(discount_amount) * quantity AS discount_amount_total
+FROM orders o 
+JOIN order_items i 
+ON o.order_id = i.order_id
+JOIN customers c 
+ON o.customer_id = c.customer_id
+GROUP BY c.customer_id
+ORDER BY item_price_total DESC
 
 -- Exercise 4
-
+SELECT c.email_address, COUNT(i.order_id) AS order_count, SUM(item_price - discount_amount) * quantity AS order_total
+FROM orders o JOIN order_items i
+ON i.order_id = o.order_id
+JOIN customers c
+ON o.customer_id = c.customer_id
+GROUP BY email_address
+HAVING COUNT(i.order_id) > 1
+ORDER BY SUM(item_price - discount_amount) * COUNT(i.order_id) DESC
 
 -- Exercise 5