Marwa Khalid - Shopify Assessment

sql/task1.sql

@@ -1,14 +1,66 @@
 -- Problem 1: Retrieve all products in the Sports category
 -- Write an SQL query to retrieve all products in a specific category.
 
+SELECT
+    product_id,
+    product_name,
+    description,
+    price,
+FROM Products
+INNER JOIN Categories ON Categories.category_id = Products.category_id
+WHERE category_name = 'Sports & Outdoors';
+
 -- Problem 2: Retrieve the total number of orders for each user
 -- Write an SQL query to retrieve the total number of orders for each user.
 -- The result should include the user ID, username, and the total number of orders.
 
+SELECT 
+    user_id,
+    username,
+    COUNT(order_id) AS total_number_of_orders
+FROM Users U
+INNER JOIN Orders ON Orders.user_id = Users.user_id
+GROUP BY U.user_id;
+
 -- Problem 3: Retrieve the average rating for each product
 -- Write an SQL query to retrieve the average rating for each product.
 -- The result should include the product ID, product name, and the average rating.
 
+SELECT 
+    product_id,
+    product_name,
+    AVG(rating) AS average_rating
+FROM Products P
+INNER JOIN Reviews ON Reviews.product_id = Products.product_id
+GROUP BY P.product_id;
+
 -- Problem 4: Retrieve the top 5 users with the highest total amount spent on orders
 -- Write an SQL query to retrieve the top 5 users with the highest total amount spent on orders.
 -- The result should include the user ID, username, and the total amount spent.
+
+-- OLD VERSION:
+/*SELECT
+    user_id,
+    username,
+    total_amount_spent
+FROM (
+    SELECT 
+        user_id,
+        username,
+        SUM(total_amount) AS total_amount_spent
+    FROM Users U
+    INNER JOIN Orders ON Orders.user_id = Users.user_id
+    GROUP BY U.user_id
+) AS T
+ORDER BY total_amount_spent DESC
+LIMIT 5;*/
+
+SELECT 
+    user_id,
+    username,
+    SUM(total_amount) AS total_amount_spent
+FROM Users U
+INNER JOIN Orders ON Orders.user_id = Users.user_id
+GROUP BY U.user_id
+ORDER BY total_amount_spent DESC
+LIMIT 5;

sql/task2.sql

@@ -3,17 +3,70 @@
 -- The result should include the product ID, product name, and the average rating.
 -- Hint: You may need to use subqueries or common table expressions (CTEs) to solve this problem.
 
+SELECT
+    product_id,
+    product_name,
+    average_rating
+FROM (
+    SELECT 
+        product_id,
+        product_name,
+        AVG(rating) AS average_rating
+    FROM Products P
+    INNER JOIN Reviews ON Reviews.product_id = Products.product_id
+    GROUP BY P.product_id;
+) AS T
+ORDER BY average_rating DESC
+LIMIT 1;
+
 -- Problem 6: Retrieve the users who have made at least one order in each category
 -- Write an SQL query to retrieve the users who have made at least one order in each category.
 -- The result should include the user ID and username.
 -- Hint: You may need to use subqueries or joins to solve this problem.
 
+SELECT
+    user_id,
+    username
+FROM (
+    SELECT 
+        user_id,
+        username,
+        COUNT(DISTINCT category_name) AS distinct_categories
+    FROM
+            Users U
+            JOIN Orders ON Orders.user_id = Users.user_id
+            JOIN Order_Items ON Order_Items.order_id = Orders.order_id
+            JOIN Products ON Products.product_id = Order_Items.product_id
+            JOIN Products ON Products.category_id = Categories.category_id
+            GROUP BY U.user_id
+) AS T
+WHERE distinct_categories = (SELECT 
+                                COUNT(DISTINCT category_id) 
+                                FROM Categories)
+
 -- Problem 7: Retrieve the products that have not received any reviews
 -- Write an SQL query to retrieve the products that have not received any reviews.
 -- The result should include the product ID and product name.
 -- Hint: You may need to use subqueries or left joins to solve this problem.
 
+SELECT 
+    product_id,
+    product_name
+FROM 
+    Products
+WHERE product_id NOT IN (SELECT 
+                            DISTINCT product_id 
+                            FROM Reviews)
+
 -- Problem 8: Retrieve the users who have made consecutive orders on consecutive days
 -- Write an SQL query to retrieve the users who have made consecutive orders on consecutive days.
 -- The result should include the user ID and username.
--- Hint: You may need to use subqueries or window functions to solve this problem.
+-- Hint: You may need to use subqueries or window functions to solve this problem.
+
+SELECT DISTINCT
+    user_id,
+    username
+FROM
+    Users
+    JOIN Orders O1 ON user_id = O1.user_idF
+    JOIN Orders O2 ON user_id = O2.user_id AND O1.order_date = DATE_ADD(O2.order_date, INTERVAL 1 DAY);

sql/task3.sql

@@ -3,17 +3,61 @@
 -- The result should include the category ID, category name, and the total sales amount.
 -- Hint: You may need to use subqueries, joins, and aggregate functions to solve this problem.
 
+SELECT
+    category_id,
+    category_name,
+    SUM(unit_price * quantity) AS total_sales_amount
+FROM
+    Categories C
+    JOIN Products ON Categories.category_id = Products.product_id
+    JOIN Order_Items ON Products.product_id = Order_Items.product_id
+GROUP BY C.category_id
+ORDER BY total_sales_amount DESC 
+LIMIT 3;
+
+
 -- Problem 10: Retrieve the users who have placed orders for all products in the Toys & Games
 -- Write an SQL query to retrieve the users who have placed orders for all products in the Toys & Games
 -- The result should include the user ID and username.
 -- Hint: You may need to use subqueries, joins, and aggregate functions to solve this problem.
 
+SELECT 
+    user_id, 
+    username
+FROM 
+    Users
+WHERE EXISTS (
+    SELECT *
+    FROM 
+        Products
+        JOIN Categories ON Products.category_id = Categories.category_id
+    WHERE 
+        category_name = 'Toys & Games'
+        AND NOT EXISTS (
+            SELECT *
+            FROM 
+                Orders
+                JOIN Order_Items OI ON Orders.order_id = Order_Items.order_id
+            WHERE 
+                Orders.user_id = Users.user_id AND Order_Items.product_id = Products.product_id
+        )
+)
+
 -- Problem 11: Retrieve the products that have the highest price within each category
 -- Write an SQL query to retrieve the products that have the highest price within each category.
 -- The result should include the product ID, product name, category ID, and price.
 -- Hint: You may need to use subqueries, joins, and window functions to solve this problem.
 
+SELECT
+    product_id,
+    product_name,
+    category_id,
+    MAX(price)
+FROM Products P
+JOIN Categories ON Categories.category_id = Products.product_id
+GROUP BY P.category_id;
+
 -- Problem 12: Retrieve the users who have placed orders on consecutive days for at least 3 days
 -- Write an SQL query to retrieve the users who have placed orders on consecutive days for at least 3 days.
 -- The result should include the user ID and username.
--- Hint: You may need to use subqueries, joins, and window functions to solve this problem.
+-- Hint: You may need to use subqueries, joins, and window functions to solve this problem.

tests/test_sql_queries.py

@@ -6,11 +6,11 @@ class TestSQLQueries(unittest.TestCase):
     def setUp(self):
         # Establish a connection to your test database
         self.conn = psycopg2.connect(
-            dbname='your_dbname',
-            user='your_username',
-            password='your_password',
+            dbname='postgres_db',
+            user='Postgres',
+            password='6292',
             host='your_host',
-            port='your_port'
+            port='5432'
         )
         self.cur = self.conn.cursor()