11 Stanley Black & Decker SQL Interview Questions (Updated 2024)

Stanley Black & Decker employees write SQL queries to analyze sales data by examining transactional records, product categories, and regional performance to optimize tool production. They also manage inventory data by tracking stock levels, shipping schedules, and supplier lead times to streamline distribution processes, which is why Stanley Black & Decker asks SQL problems during interviews for Data Science, Data Engineering and Data Analytics jobs.

As such, to help you ace the Stanley Black & Decker SQL interview, we'll cover 11 Stanley Black & Decker SQL interview questions in this article.

11 Stanley Black & Decker SQL Interview Questions

SQL Question 1: Identify the top purchasing Stanley Black & Decker customers.

Given two tables and , write a SQL query to identify the customers who has made the most purchases in the last 12 months. Assume that the more a customer purchases, the more important the customer is to the business. In case of a tie, users with the most recent purchase should take precedence.

Please note, a is flagged by a non-null .

Here's what the and tables look like:

Example Input:

Example Input:

Answer:

In this query, we join the and tables on , before filtering for purchases made in the last year using the WHERE clause. We then group the results by , , and , and count the total number of purchases for each customer. We then order the results by the total number of purchases and the most recent purchase date, before limiting the results to the top 10 customers.

To solve a similar power-user data analysis problem question on DataLemur's free online SQL code editor, try this recently asked Microsoft SQL interview question:

SQL Question 2: Highly-Paid Employees

Suppose you had a table of Stanley Black & Decker employee salaries. Write a SQL query to find all employees who earn more than their direct manager.

Stanley Black & Decker Example Input:

Example Output:

This is the output because Olivia Smith earns $8,000, surpassing her manager, William Davis who earns 7,800.

Write a SQL query for this problem directly within the browser on DataLemur:

Answer:

First, we perform a SELF-JOIN where we treat the first table () as the managers' table and the second table () as the employees' table. Then we use a clause to filter the results, ensuring we only get employees whose salaries are higher than their manager's salary.

If the solution above is hard to understand, you can find a detailed solution here: Employees Earning More Than Their Boss.

SQL Question 3: What's the purpose of a foreign key?

A foreign key is a field in a database table that serves as a reference to the primary key of another table, allowing for the creation of a relationship between the two tables.

For a concrete example, let's inspect employee data from Stanley Black & Decker's HR database:

:

In this table, is the primary key, and is used to uniquely identify each row.

could be a foreign key. It references the of the manager of each employee in the table, establishing a relationship between the employees and their managers. This foreign key allows you to easily query the table to find out who a specific employee's manager is, or to find out which employees report to a specific manager.

It is possible for a table to have multiple foreign keys that reference primary keys in different tables. For instance, the table could have additional foreign keys for the of the department where an employee works and the of the employee's location.

SQL Question 4: Calculate the Monthly Average Sales of Each Product

As a data analyst at Stanley Black & Decker, your task is to help the sales team understand the monthly sales performance of each product. You are provided with a table that has records of all the sales including the associated product, the quantity sold, and the date of the transaction.

Write a SQL query to find the average units sold per month for each product using the window function.

Example Input:

Example Output:

Answer:

In this solution, we first extract the month from the using the function. Next, we calculate the average quantity sold per month for each product using the window function, partitioned by the and the extracted month. The results are then ordered by month and product_id. The clause is used to apply the function to each partition of the result set. Thus, giving us the monthly average sales for each product.

To solve a similar window function interview problem which uses RANK() on DataLemur's free interactive SQL code editor, try this Amazon SQL question asked in a BI Engineer interview:

SQL Question 5: What does do, and when would you use this SQL command?

When using , only rows that are identical in both sets will be returned.

For a concrete example, say you were a Data Analyst supporting the Sales Analytics team at Stanley Black & Decker, and data on potential sales leads lived in both Salesforce and Hubspot CRMs. To write a query to analyze leads created before 2023 started, that show up in BOTH CRMs, you would use the command:

SQL Question 6: Analyze Sales of Stanley Black & Decker

Stanley Black & Decker is interested in optimizing its production scheduling and inventory management by analyzing previous sales data. The company has a database that notes each tool sold, the location where it was sold, and the date of the sale. The company is interested specifically in the following question:

What tool category has been the most popular each month of the last year in each sales location?

Here is an example of how the database tables might be structured:

Example Input:

Example Input:

Answer:

In PostgreSQL, you might use an SQL query like the below to solve this:

This PostgreSQL query works in two steps. The first step groups each sale by its category, month, and location, and gets the total quantity sold for each grouping. The second step then selects the most popular tool category (highest quantity) for each month and location. The final query combines these two steps to reveal the most popular category by month and location.

SQL Question 7: Can you explain what / SQL commands do?

Note: interviews at Stanley Black & Decker often aren't trying to test you on a specific flavor of SQL. As such, you don't need to exactly know that is available in PostgreSQL and SQL Server, while MINUS is available in MySQL and Oracle – you just need to know the general concept!

Your answer should mention that the / operator is used to remove to return all rows from the first SELECT statement that are not returned by the second SELECT statement.

Here's a PostgreSQL example of using EXCEPT to find all of Stanley Black & Decker's Facebook video ads with more than 50k views that aren't also being run on YouTube:

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.

SQL Question 8: Filter Customer Tool Purchases

Stanley Black & Decker need to analyze their customers' purchasing behavior in relation to various tools on different days of the week. Write a SQL query that fetches customer records who made purchases on the weekends (Saturday and Sunday) and bought either power drills or hand saws.

Example Input:

Example Output:

Answer:

This query uses EXTRACT function to fetch the day of week from the purchase_date, where '0' represents Sunday and '6' represents Saturday. It also filters out rows where the tool_type is either 'Hand Saw' or 'Power Drill'.

SQL Question 9: Finding the Average Time Taken for Order Fulfillment

As a data analyst for Stanley Black & Decker, your manager wants to assess the efficiency of the order fulfillment process. Your task is to find the average time (in days) it takes for an order to be processed and shipped after it has been placed. This timeframe is calculated as the difference between the order placement date and the shipping date.

Example Input:

Example Output:

Answer:

This SQL query extracts the number of days between the order placement date and the shipping date for each order. It then calculates the average number of days taken for orders of each product to be processed and shipped. By grouping by the , the answer gives the average time taken per product.

To practice a very similar question try this interactive Alibaba Compressed Mean Question which is similar for calculating averages from order data or this Amazon Server Utilization Time Question which is similar for calculating time between specific events.

SQL Question 10: What sets the 'BETWEEN' and 'IN' operators apart?

While both the and operators are used to filter data based on some criteria, selects for values within a given range, whereas for it checks if the value is in a given list of values.

For example, say you had a table called , which had the salary of the employee, along with the country in which they reside.

To find all employees who made between $80k and$120k, you could use the operator:

To find all employees that reside in the US or Canada, you could use the operator:

SQL Question 11: Click-Through Rates for Stanley Black & Decker Ads

Stanley Black & Decker, a global provider of industrial tools and household hardware, runs multiple digital advertising campaigns. From these campaigns, they collect data on the number of ad impressions (how many times an ad was displayed) and the number of users who clicked on the ad, leading to their website. The goal is to analyze the click-through-rate (CTR) of these ads which is calculated as ( number of clicks / number of impressions ) * 100.

Your task is to write a PostgreSQL query that calculates the weekly CTR for each ad.

Example Input:

Answer:

Here's the SQL query:

The output would ideally display the calculated click-through rates, rounded to two decimal places:

Example Output:

After running this query, you would be able to analyze the weekly CTR for each advertisement, allowing Stanley Black & Decker to assess the effectiveness of their digital advertising strategy.

To solve a similar problem about calculating rates, try this TikTok SQL question on DataLemur's online SQL code editor:

Stanley Black & Decker SQL Interview Tips

The best way to prepare for a SQL interview, besides making sure you have strong SQL fundamentals, is to practice a ton of real SQL questions that were asked in recent job interviews. Besides solving the earlier Stanley Black & Decker SQL interview questions, you should also solve the 200+ FAANG SQL Questions on DataLemur which come from companies like Google, Uber, and Microsoft.

Each problem on DataLemur has hints to guide you, detailed solutions and crucially, there's an interactive SQL code editor so you can easily right in the browser your SQL query answer and have it graded.

To prep for the Stanley Black & Decker SQL interview you can also be useful to solve interview questions from other consumer good companies like:

• Colgate-Palmolive SQL questions
• Kimberly-Clark SQL questions
• Procter & Gamble SQL questions
• Spectrum Brands SQL questions

In case your SQL query skills are weak, don't worry about jumping right into solving questions – refresh your SQL knowledge with this interactive SQL tutorial.

This tutorial covers topics including LEAD/LAG window functions and finding NULLs – both of which show up routinely in Stanley Black & Decker SQL interviews.

Stanley Black & Decker Data Science Interview Tips

What Do Stanley Black & Decker Data Science Interviews Cover?

In addition to SQL interview questions, the other question categories to practice for the Stanley Black & Decker Data Science Interview include:

• Probability & Stats Questions
• Python or R Coding Questions
• Product Analytics Questions
• ML Modelling Questions
• Behavioral Questions focussed on Stanley Black & Decker values & principles

Dive into the latest news and stories from Stanley Black & Decker and discover how they're driving innovation in the industry!

How To Prepare for Stanley Black & Decker Data Science Interviews?

To prepare for Stanley Black & Decker Data Science interviews read the book Ace the Data Science Interview because it's got:

• 201 interview questions sourced from companies like Microsoft, Google & Amazon
• a refresher on SQL, AB Testing & ML
• over 1000+ reviews on Amazon & 4.5-star rating

Don't ignore the behavioral interview – prep for that using this guide on behavioral interview questions.