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How-to-code-subqueries.sql

@@ -1,19 +1,35 @@
 -- 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
-
+???
 
 -- Exercise 4 Part 2
-
+???
 
 -- Exercise 5
-
+???
 
 -- Exercise 6
+???

How-to-code-summary-queries.sql

@@ -1,19 +1,36 @@
 -- Exercise 1
-
+SELECT COUNT(*) AS orders, SUM(tax_amount) AS tax
+FROM orders;
 
 -- Exercise 2
-
+SELECT cat.category_name, list_price, COUNT(*) AS product_count
+FROM categories cat
+JOIN products pro ON cat.category_id = pro.category_id
+GROUP BY category_name
+ORDER BY product_count DESC
+LIMIT 1;
 
 -- Exercise 3
-
+SELECT email_address, SUM(item_price) * quantity AS sum_price, SUM(discount_amount) * quantity AS sum_discount
+FROM customers cus
+JOIN orders ord ON ord.customer_id = cus.customer_id
+JOIN order_items oi ON oi.order_id = ord.order_id
+GROUP BY email_address
+ORDER BY sum_price DESC;
 
 -- Exercise 4
-
+SELECT email_address, COUNT(*) AS order_count, (item_price - discount_amount) * quantity AS total_amount
+FROM customers cus
+JOIN orders ord ON cus.customer_id = ord.customer_id
+JOIN order_items oid ON ord.customer_id = oid.order_id 
+GROUP BY email_address HAVING order_count > 1
+ORDER BY total_amount DESC;
 
 -- Exercise 5
-
+???
 
 -- Exercise 6
-
+???
 
 -- Exercise 7
+???

How-to-insert-update-and-delete-data.sql

@@ -1,30 +1,40 @@
 -- Exercise 1
-
+INSERT INTO categories (category_name)
+VALUES ('Brass')
 
 -- Exercise 2
-
+???
 
 -- Exercise 3
-
+DELETE FROM categories
+WHERE category_id = 5
 
 -- Exercise 4
-
+INSERT INTO products(category_id, product_code, product_name, description, list_price, discount_percent, date_added)
+VALUES (4, 'dgx_640', 'Yamaha DGX 640 88-Key Digital Piano', 'Long description to come.', 799.99, 0, now())
 
 -- Exercise 5
-
+UPDATE products
+SET discount_percent = 35
+WHERE product_id = 11
 
 -- Exercise 6
-
+???
 
 -- Exercise 7
-
+INSERT INTO customers(email_address, password, first_name, last_name)
+VALUES ('rick@raven.com', ' ', 'Rick', 'Raven')
 
 -- Exercise 8
-
+UPDATE customers
+SET password = "secret"
+WHERE email_address = 'rick@raven.com'
 
 -- Exercise 9
-
+UPDATE customers
+SET password = "reset"
+LIMIT 100
 
 -- Exercise 10
-
+///
 

How-to-retrieve-data-from-a-single-table.sql

@@ -1,22 +1,48 @@
 -- Exercise 1
-
+SELECT product_name, list_price, date_added, discount_percent
+FROM products
+ORDER BY list_price DESC;
 
 -- Exercise 2
-
+SELECT first_name, last_name,
+CONCAT(first_name, ', ', last_name) AS last_name
+FROM customers
+WHERE last_name > 'M'
+ORDER BY last_name ASC;
 
 -- Exercise 3
-
+SELECT product_name, list_price, date_added
+FROM products
+WHERE list_price > 500 AND list_price < 2000
+ORDER BY date_added DESC;
 
 -- Exercise 4
-
+SELECT product_name, list_price, discount_percent,
+ROUND(((list_price * discount_percent) / 100), 2) AS discount_amount,
+ROUND(((list_price - (list_price * discount_percent) / 100)), 2) AS discount_price
+FROM products
+ORDER BY discount_price DESC
+LIMIT 5;
 
 -- Exercise 5
-
+SELECT item_id, item_price, discount_amount, quantity,
+item_price * quantity AS price_total,
+discount_amount * quantity AS discount_total,
+(item_price - discount_amount) * quantity AS item_total
+FROM order_items
+HAVING item_total > 500
+ORDER BY item_total DESC;
 
 -- Exercise 6
-
+SELECT order_id, order_date, ship_date
+FROM orders
+WHERE ship_date IS NULL;
 
 -- Exercise 7
+SELECT NOW() AS today_unformatted,
+DATE_FORMAT(NOW(), '%e-%b-%Y') AS today_formatted;
 
-
+-- Exercise 8
+SELECT 100 AS price, .07 AS tax_rate,
+100 * .07 AS tax_amount,
+100 + (100 * .07) AS total;

How-to-retrieve-data-from-two-or-more-tables.sql

@@ -1,19 +1,35 @@
 -- Exercise 1
-
+SELECT category_name, product_name, list_price
+FROM categories JOIN products
+ORDER BY category_name, list_price ASC;
 
 -- Exercise 2
-
+SELECT first_name, last_name, line1, city, state, zip_code
+FROM customers c1 JOIN addresses c2 ON c1.customer_id = c2.customer_id
+WHERE email_address = 'allan.sherwood@yahoo.com';
 
 -- Exercise 3
-
+SELECT first_name, last_name, line1, city, state, zip_code
+FROM customers c1 JOIN addresses c2 ON c1.customer_id = c2.customer_id
+?????
 
 -- Exercise 4
-
+SELECT last_name, first_name, order_date, product_name, item_price, discount_amount, quantity
+FROM customers c
+JOIN orders o ON c.customer_id = o.customer_id
+JOIN order_items oi ON o.order_id = oi.order_id
+JOIN products p ON oi.product_id = p.product_id
+ORDER BY last_name, order_date, product_name;
 
 -- Exercise 5
-
+SELECT DISTINCT p1.product_name, p2.list_price
+FROM products p1 JOIN products p2
+ON p1.product_id != p2.product_id
+AND p1.list_price = p2.list_price
+ORDER BY product_name;
 
 -- Exercise 6
-
+???
 
 -- Exercise 7
+???