Tempur Sealy employees write SQL queries to analyze sales data by product category, region, and customer segment to predict sales trends and identify opportunities for growth. It is also used to manage and optimize the manufacturing inventory by analyzing customers' purchase behavior data, including repeat business and warranty claims, the reason why Tempur Sealy asks SQL coding questions in interviews for Data Science, Analytics, and & Data Engineering jobs.
Thus, to help you ace the Tempur Sealy SQL interview, here’s 10 Tempur Sealy SQL interview questions in this blog.
In Tempur Sealy, a company well known for their mattresses and bedding products, power customers are defined as those who have made the highest number of purchases within the last year. As a data analyst, you are required to write a SQL query that lists the top 5 power customers based on the number of purchases.
The database is structured as follows:
customers
:customer_id | first_name | last_name |
---|---|---|
101 | John | Doe |
102 | Jane | Smith |
103 | Alice | Johnson |
orders
:order_id | customer_id | order_date | product_id | quantity |
---|---|---|---|---|
8001 | 101 | 06/10/2022 | 50001 | 1 |
8002 | 102 | 06/18/2022 | 50001 | 2 |
8003 | 101 | 06/20/2022 | 50001 | 1 |
8004 | 103 | 07/01/2022 | 50002 | 1 |
8005 | 102 | 07/12/2022 | 50002 | 1 |
8006 | 101 | 07/14/2022 | 50002 | 2 |
Your output should list the customer_id, first_name and last_name of the top 5 power customers, as well as the number of orders each customer has placed.
Note: If there are multiple customers with the same number of orders tiebreak by order frequency and then by customer_id in ascending order.
SELECT c.customer_id, c.first_name, c.last_name, COUNT(o.order_id) AS num_orders FROM customers c JOIN orders o ON c.customer_id = o.customer_id WHERE o.order_date >= (CURRENT_DATE - INTERVAL '1 YEAR') GROUP BY c.customer_id ORDER BY num_orders DESC, c.customer_id ASC LIMIT 5;
This query first joins the customers
table with the orders
table on the customer_id
field. It then groups the results by customer, and counts the number of orders each customer has placed within the last year. The results are ordered by number of orders in descending order, and by customer_id
in ascending order. Finally, the query returns the top 5 customers with the highest number of orders.
To solve a related customer analytics question on DataLemur's free online SQL code editor, try this recently asked Microsoft SQL interview question:
Assume you had a table of Tempur Sealy employee salaries, along with which department they belonged to. Write a query to compare the average salary of employees in each department to the company's average salary for March 2024. Return the comparison result as 'higher', 'lower', or 'same' for each department. Display the department ID, payment month (in MM-YYYY format), and the comparison.
Code your solution to this interview question and run your code right in DataLemur's online SQL environment:
The answer is LONG – 30+ lines of SQL. You can find a detailed solution here: Department Salaries.
To explain the difference between a primary key and foreign key, let's start with an example Tempur Sealy sales database:
tempur_sealy_sales
:order_id | product_id | customer_id | quantity |
---|---|---|---|
1 | 303 | 1 | 2 |
2 | 404 | 1 | 1 |
3 | 505 | 2 | 3 |
4 | 303 | 3 | 1 |
In this table, order_id
could be a primary key. It is unique for each row in the table and cannot contain null values.
product_id
and customer_id
could both be foreign keys. They reference the primary keys of other tables, such as a Products table and a Customers table, respectively. This establishes a relationship between the tempur_sealy_sales
table and the other tables, such that each row in the sales database corresponds to a specific product and a specific customer.
Tempur Sealy is a well-known maker of mattresses and related products. They continuously monitor customer reviews and ratings for each product and use this data to improve their offerings. Your task is to write a SQL query that calculates the average rating of each product on a monthly basis.
For simplicity, you can assume that the reviews
table has the following schema:
reviews
Example Input:review_id | user_id | submit_date | product_id | stars |
---|---|---|---|---|
1 | 123 | 2022-06-08 | 50001 | 4 |
2 | 265 | 2022-06-10 | 69852 | 4 |
3 | 362 | 2022-06-18 | 50001 | 3 |
4 | 192 | 2022-07-26 | 69852 | 3 |
5 | 981 | 2022-07-05 | 69852 | 2 |
The result should be a table that lists the average rating (stars
) for each product (product_id
) by month. The output should look like this:
month | product_id | avg_stars |
---|---|---|
6 | 50001 | 3.5 |
6 | 69852 | 4.0 |
7 | 69852 | 2.5 |
Here is one way to write the query using PostgreSQL:
SELECT EXTRACT(MONTH FROM submit_date) AS month, product_id, AVG(stars) AS avg_stars FROM reviews GROUP BY month, product_id ORDER BY month, product_id;
This query uses the EXTRACT
function to get the month from the submit_date
field. It then groups the records by both month and product, averaging the stars for each group. This result is then ordered by month and product_id to make it easier to interpret.
To solve a similar window function question on DataLemur's free online SQL code editor, solve this Google SQL Interview Question:
INTERSECT
command?Similar to the UNION
and EXCEPT
/MINUS
operators, the PostgreSQL INTERSECT operator combines result sets of two or more SELECT
statements into a single result set. However, INTERSECT
only returns the rows that are in BOTH select statements.
For a concrete example, say you were on the Sales Analytics team at Tempur Sealy, and had data on sales leads exported from both HubSpot and Salesforce CRMs in two different tables. To write a query to analyze leads created after 2023 started, that show up in both CRMs, you would use the INTERSECT
command:
SELECT email, job_title, company_id FROM tempur_sealy_hubspot_leads WHERE created_at > '2023-01-01' INTERSECT SELECT email, job_title, company_id FROM tempur_sealy_sfdc_leads WHERE created_at > '2023-01-01';
As an analyst at Tempur Sealy, a manufacturing company that develops mattresses, your task is to optimize production planning and marketing efforts. Design a database schema that captures sales data. This should include tables for sales
, mattresses
, and stores
. Use this schema to answer the following questions:
sales
Example Input:sale_id | mattress_id | store_id | sale_date | units_sold | sale_amount |
---|---|---|---|---|---|
1 | 101 | 201 | 2022-10-01 | 5 | 5000 |
2 | 101 | 202 | 2022-10-02 | 3 | 3000 |
3 | 102 | 203 | 2022-10-02 | 2 | 4000 |
4 | 103 | 201 | 2022-10-03 | 1 | 2000 |
5 | 104 | 204 | 2022-10-04 | 4 | 8000 |
mattresses
Example Input:mattress_id | model_name |
---|---|
101 | "Tempur-ProAdapt" |
102 | "Tempur-LuxeAdapt" |
103 | "Tempur-breeze" |
104 | "Tempur-Cloud" |
stores
Example Input:store_id | store_name |
---|---|
201 | "Store-1" |
202 | "Store-2" |
203 | "Store-3" |
204 | "Store-4" |
The answer to these questions would involve joining tables and aggregating data. Here are the statements for the given questions:
SELECT m.model_name, SUM(s.units_sold) as total_units, SUM(s.sale_amount) as total_sales FROM sales s JOIN mattresses m ON s.mattress_id = m.mattress_id GROUP BY m.model_name ORDER BY total_units DESC, total_sales DESC LIMIT 1;
SELECT st.store_name, SUM(s.units_sold) as total_units FROM sales s JOIN stores st ON s.store_id = st.store_id GROUP BY st.store_name ORDER BY total_units DESC LIMIT 1;
SELECT date_part('dow', s.sale_date) as day_of_week, COUNT(*) as total_sales FROM sales s GROUP BY day_of_week ORDER BY total_sales DESC LIMIT 1;
These queries will answer the questions by aggregating sales data: the sum of units sold and sales amounts, grouped by mattress model name or store name, and then order the results in descending order to identify the top seller. The last query uses the date_part
function to extract the day of the week from the date, and then groups data by this to identify the most popular sale day.
A self-join is a JOIN
operation in which a single table is joined to itself. To perform a self-join, you must specify the table name twice in the FROM
clause, giving each instance a different alias. You can then join the two instances of the table using a JOIN
clause, and specify the relationship between the rows in a WHERE
clause.
Think of using a self-joins whenever your data analysis involves analyzie pairs of the same things, like comparing the salaries of employees within the same department, or identifying pairs of products that are frequently purchased together (which you can do in this real SQL question from a Walmart interview).
For another self-join example, suppose you were conducting an HR analytics project and needed to examine how frequently employees within the same department at Tempur Sealy interact with one another, you could use a self-join query like the following to retrieve all pairs of Tempur Sealy employees who work in the same department:
SELECT e1.name AS employee1, e2.name AS employee2 FROM tempur_sealy_employees AS e1 JOIN tempur_sealy_employees AS e2 ON e1.department_id = e2.department_id WHERE e1.id <> e2.id;
This query returns all pairs of Tempur Sealy employees who work in the same department, and excludes pairs where the employee's id is the same (since this would represent the same Tempur Sealy employee being paired with themselves).
As a data analyst at Tempur Sealy, you are required to analyze recent customer transactions. Write a SQL query to filter down a customers
database where product_id
is 50001 or 69852, the purchase_date
is after '06/01/2022' and the purchase_amount
is higher than $800.
customers
Example Input:customer_id | product_id | purchase_date | purchase_amount | payment_method |
---|---|---|---|---|
9591 | 50001 | 06/10/2022 00:00:00 | 900 | Credit |
8028 | 35000 | 06/29/2022 00:00:00 | 500 | Paypal |
8523 | 69852 | 05/31/2022 00:00:00 | 950 | Credit |
9394 | 50001 | 07/01/2022 00:00:00 | 850 | Debit |
7625 | 69852 | 07/19/2022 00:00:00 | 950 | Credit |
customer_id | product_id | purchase_date | purchase_amount | payment_method |
---|---|---|---|---|
9591 | 50001 | 06/10/2022 00:00:00 | 900 | Credit |
9394 | 50001 | 07/01/2022 00:00:00 | 850 | Debit |
7625 | 69852 | 07/19/2022 00:00:00 | 950 | Credit |
SELECT * FROM customers WHERE product_id IN (50001, 69852) AND purchase_date > '06/01/2022' AND purchase_amount > 800;
This PostgreSQL query filters down recent customer transactions by product, purchase date, and purchase amount. It uses WHERE to apply the filtering conditions, AND to combine these conditions, and IN to specify multiple possible values for the product_id field.
You are an analyst at Tempur Sealy, a company that deals in mattresses. You have been provided with a table called reviews
that contains data on customer reviews for different mattress models. Each row in the table represents one review, and includes the date of the review (submit_date
), the unique identifier of the mattress reviewed (product_id
), and the rating given by the customer (stars
) as an integer between 1 and 5.
Your task is to find the average rating (avg_stars
) for each mattress model on a monthly basis.
reviews
Example Input:review_id | submit_date | product_id | stars |
---|---|---|---|
1001 | 2022-01-15 | 201 | 3 |
1002 | 2022-02-20 | 202 | 4 |
1003 | 2022-01-18 | 201 | 5 |
1004 | 2022-01-22 | 202 | 3 |
1005 | 2022-02-10 | 202 | 4 |
1006 | 2022-01-30 | 201 | 4 |
1007 | 2022-02-02 | 202 | 1 |
1008 | 2022-02-15 | 201 | 2 |
month | product_id | avg_stars |
---|---|---|
2022-01 | 201 | 4.00 |
2022-02 | 201 | 2.00 |
2022-01 | 202 | 3.00 |
2022-02 | 202 | 3.00 |
SELECT DATE_TRUNC('month', submit_date) AS month, product_id, AVG(stars) AS avg_stars FROM reviews GROUP BY DATE_TRUNC('month', submit_date), product_id;
In this SQL query, we first truncate the submit_date
to a monthly basis using the DATE_TRUNC
function, which allows us to group by month. We then use the AVG
function to find the average stars
for each group of reviews, with groups defined by their product_id
and month
. This gives us the average rating for each product on a monthly basis.
To practice a very similar question try this interactive Amazon Average Review Ratings Question which is similar for calculating average ratings or this Wayfair Y-on-Y Growth Rate Question which is similar for using dates in analysis.
EXCEPT
/ MINUS
do?The MINUS
/EXCEPT
operator is used to remove to return all rows from the first SELECT statement that are not returned by the second SELECT statement.
Note that EXCEPT
is available in PostgreSQL and SQL Server, while MINUS is available in MySQL and Oracle (but don't stress about knowing which DBMS supports what exact commands since the interviewers at Tempur Sealy should be lenient!).
Here's a PostgreSQL example of using EXCEPT to find all of Tempur Sealy's Facebook video ads with more than 10k views that aren't also being run on YouTube:
SELECT ad_creative_id FROM tempur_sealy_facebook_ads WHERE views > 10000 AND type=video EXCEPT SELECT ad_creative_id FROM tempur_sealy_youtube_ads
If you want to retain duplicates, you can use the EXCEPT ALL operator instead of EXCEPT. The EXCEPT ALL operator will return all rows, including duplicates.
The best way to prepare for a Tempur Sealy SQL interview is to practice, practice, practice. In addition to solving the above Tempur Sealy SQL interview questions, you should also solve the 200+ SQL Interview Questions on DataLemur which come from companies like Google, Facebook, Microsoft and Amazon.
Each DataLemur SQL question has multiple hints, fully explained answers along with a discussion board to see how others solved it and best of all, there is an interactive SQL code editor so you can right in the browser run your SQL query answer and have it checked.
To prep for the Tempur Sealy SQL interview it is also useful to practice SQL problems from other consumer good companies like:
But if your SQL coding skills are weak, forget about jumping right into solving questions – refresh your SQL knowledge with this free SQL tutorial.
This tutorial covers things like removing NULLs and creating pairs via SELF-JOINs – both of these show up routinely in Tempur Sealy SQL interviews.
Stay up-to-date on the latest news and developments from Tempur Sealy with their press releases!
Besides SQL interview questions, the other types of questions to prepare for the Tempur Sealy Data Science Interview are:
I think the optimal way to prepare for Tempur Sealy Data Science interviews is to read the book I wrote: Ace the Data Science Interview.
It covers 201 interview questions sourced from tech companies like Netflix, Google, & Airbnb. The book's also got a refresher covering SQL, Product-Sense & ML. And finally it's vouched for by the data community, which is why it's got over 1000+ 5-star reviews on Amazon.
While the book is more technical in nature, it's also important to prepare for the Tempur Sealy behavioral interview. Start by reading the company's cultural values.