finished exercises 1-3, start ex4

How-to-code-subqueries.sql

@@ -1,14 +1,33 @@
 -- Exercise 1
 
+SELECT DISTINCT category_name
+FROM categories
+WHERE category_id IN (SELECT category_id
+						FROM products)
+ORDER BY category_name;
 
 -- Exercise 2
 
+SELECT product_name,
+	list_price
+FROM products
+WHERE list_price > (SELECT AVG(list_price)
+					FROM products)
+ORDER BY list_price DESC;
 
 -- Exercise 3
 
+SELECT category_name
+FROM categories
+WHERE NOT EXISTS (SELECT *
+					FROM products
+                    WHERE category_id = categories.category_id);
 
 -- Exercise 4
 
+SELECT email_address,
+	order_id,
+	
 
 -- Exercise 4 Part 2