oef1-7

How-to-code-summary-queries.sql

@@ -1,19 +1,77 @@
+-- Exercise 1 --
+SELECT 
+	COUNT(order_id),
+    SUM(tax_amount)
+FROM orders;
 
+-- Exercise 2 --
+SELECT
+	category_name,
+    COUNT(product_id),
+    MAX(list_price)
+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
+	email_address,
+    SUM(item_price) * quantity,
+    SUM(discount_amount) * quantity
+FROM orders ord  JOIN order_items o
+	ON o.order_id = ord.order_id
+    JOIN customers c
+    ON ord.customer_id = c.customer_id
+GROUP BY c.customer_id
+ORDER BY item_price DESC;
 
+-- Exercise 4 --
+SELECT
+	c.email_address AS 'Email',
+    COUNT(o.order_id) AS 'Order Count',
+    SUM(item_price - discount_amount) * quantity AS 'Total Amount'
+FROM orders ord  JOIN order_items o
+	ON o.order_id = ord.order_id
+    JOIN customers c
+    ON ord.customer_id = c.customer_id
+GROUP BY email_address
+HAVING COUNT(o.order_id) > 1
+ORDER BY SUM(item_price - discount_amount) * COUNT(o.order_id)  DESC;
 
 
 
+-- Exercise 5 --
+SELECT
+	email_address,
+    COUNT(o.order_id),
+    SUM(item_price - discount_amount) * quantity AS 'Total Amount'
+FROM orders ord  JOIN order_items o
+	ON o.order_id = ord.order_id
+    JOIN customers c
+    ON ord.customer_id = c.customer_id
+WHERE o.item_price > 400
+GROUP BY email_address
+HAVING COUNT(o.order_id) > 1
+ORDER BY SUM(item_price - discount_amount) * COUNT(o.order_id)  DESC;
 
+-- oef niet juist, 1 bedrag klopt niet. Ik vind de fout niet --
+-- Exercise 6 --
+SELECT
+	product_name,
+    SUM(item_price - discount_amount) * quantity AS 'Total Amount'
+FROM products p JOIN order_items ord 
+	ON p.product_id = ord.product_id
+GROUP BY product_name WITH ROLLUP;
 
+-- Exercise 7 --
+SELECT 
+	email_address,
+    COUNT(product_id) AS number_of_products
+FROM customers c JOIN orders o
+	ON c.customer_id = o.customer_id
+JOIN order_items ord 
+	ON o.order_id = ord.order_id
+GROUP BY email_address
+HAVING COUNT(o.order_id) > 1;
 
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