9 Kraft Heinz SQL Interview Questions (Updated 2024)

Updated on

October 31, 2024

Data Analysts and Data Engineers at Kraft Heinz use SQL for analyzing sales data to find market trends, allowing them to adjust their strategies based on consumer preferences. They also manage supply chain data through SQL to maintain efficient inventory control, ensuring that products are available when they are needed, this is why Kraft Heinz ask SQL problems during interviews.

So, to help you study, we've curated 9 Kraft Heinz SQL interview questions – can you answer each one?

Kraft Heinz SQL Interview Questions

9 Kraft Heinz SQL Interview Questions

SQL Question 1: Average Rating of Each Product per Month

As part of Kraft Heinz's product marketing team, you have been asked to analyze the feedback data received from customers. Specifically, the team wants to understand the average ratings of each product on a monthly basis to identify trends or problematic issues that might need to be addressed. You decide to use SQL window functions to solve this problem.

Example Input:

review_iduser_idsubmit_dateproduct_idstars
61711232022-06-08500014
78022652022-06-10698524
52933622022-06-18500013
63521922022-07-26698523
45179812022-07-05698522

Example Output:

monthproduct_idavg_stars
6500013.5
6698524.0
7698522.5

Answer:


This SQL query uses window function . It calculates the average () stars of the same product () in the same month (). The clause is used to arrange the output by month and product_id, making it easier to read.

p.s. Window functions show up super often during SQL interviews, so practice the 27+ window function questions on DataLemur

DataLemur Window Function SQL Questions

SQL Question 2: Well Paid Employees

Assume there was a table of Kraft Heinz employee salaries. Write a SQL query to find the employees who earn more than their direct manager.

Kraft Heinz Example Input:

employee_idnamesalarydepartment_idmanager_id
1Emma Thompson38001
2Daniel Rodriguez2230110
3Olivia Smith800018
4Noah Johnson680028
5Sophia Martinez1750110
8William Davis70002NULL
10James Anderson40001NULL

Example Output:

employee_idemployee_name
3Olivia Smith

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

Check your SQL query for this question and run your code right in DataLemur's online SQL environment:

Employees Earning More Than Their Manager

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 confusing, you can find a step-by-step solution here: Employee Salaries Higher Than Their Manager.

SQL Question 3: What are the main differences between foreign and primary keys in a database?

To explain the difference between a primary key and foreign key, let's inspect employee data from Kraft Heinz's HR database:

:

Here’s the table reformatted to match your example:

employee_idfirst_namelast_namemanager_id
1AubreyGraham3
2MarshalMathers3
3DwayneCarter4
4ShawnCarter

In this table, could be a primary key. It is unique for each row in the table and cannot contain null values.

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 also possible for a table to have multiple foreign keys that reference different primary keys in other tables. For example, the table could have additional foreign keys for the of the department where each employee works, and the l of the location where each employee is based.

Kraft Heinz SQL Interview Questions

SQL Question 4: Track Product Inventory Status

As a Kraft Heinz data specialist, you have been tasked with managing the company's product inventory. The company wants to keep track of each product’s inventory status over time. Your task is to model the tables, define the relationships, and choose the appropriate columns for these tables.

Furthermore, Kraft Heinz wants to know the inventory status of their products by the end of each month. The inventory status should include product name, quantity of product left in inventory, and whether the inventory level for the product is LOW (less than 10 items), MEDIUM (between 10 and 50 items), or HIGH (more than 50 items).

Assume the following tables:

Example Input:

product_idproduct_name
1001Kraft Mac & Cheese
1002Heinz Ketchup
1003Planters Peanuts

Example Input:

inventory_idproduct_iddatequantity
110012022-06-3060
210022022-06-3015
310032022-06-305
410012022-07-3170
510022022-07-3120
610032022-07-318

Answer:


This query joins the and tables on . It formats the column to show only year and month (). It also creates a new column that categorizes the quantity into 'LOW', 'MEDIUM', or 'HIGH'. This output provides the inventory status by month for each product, which can help Kraft Heinz with managing their product inventory effectively.

SQL Question 5: What is a SQL constraint?

A constraint ensures that all values in a column are different. It is often used in conjunction with other constraints, such as NOT NULL, to ensure that the data meets certain conditions.

For example, if you had Kraft Heinz sales leads data stored in a database, here's some constraints you'd use:


In this example, the constraint is applied to the and fields to ensure that each Kraft Heinz lead has a unique email address and phone number. This helps to ensure the integrity of the data in the database and prevents errors that could occur if two leads had the same email address or phone number.

SQL Question 6: Determine the Average Price of All Sold Products

As a data analyst at Kraft Heinz, you have been asked to determine the average selling price of items in each product category for the first quarter of the year 2022. Kraft Heinz has a broad range of products and they would like to understand the average sales price on a per category basis to inform their pricing strategies.

Example Input:

product_idproductnamecategory
101KetchupCondiments
102MustardCondiments
103Mac & CheesePrepared Foods
104AlmondsSnacks

Example Input:

sales_idproduct_idsales_dateselling_price
20110101/15/20222.5
20210202/18/20222
20310103/30/20222.5
20410301/23/20223.5
20510401/12/20225
20610402/19/20224.5
20710403/29/20225

Answer:


This SQL query joins the and tables using the field. It then restricts the data to only sales made in the first quarter of 2022 using the function, then it groups rows by product and calculates the average selling price of products by category. The final result would list down product categories along with their average selling price in the specified period.

To practice a very similar question try this interactive Amazon Highest-Grossing Items Question which is similar for calculating metrics for categories or this Amazon Average Review Ratings Question which is similar for aggregating data by time and category.

SQL Question 7: How are and similar, and how are they different?

Both the and window functions are used to access a row at a specific offset from the current row.

However, the function retrieves a value from a row that follows the current row, whereas the function retrieves a value from a row that precedes the current row.

Say you had a table of salary data for Kraft Heinz employees:

namesalary
Amanda130000
Brandon90000
Carlita80000

You could use the function to output the salary of each employee, along with the next highest-paid employee:


This would yield the following output:

namesalarynext_salary
Amanda13000090000
Brandon9000080000
Carlita80000NULL

Swapping for would get you the salary of the person who made just more than you:

namesalarynext_salary
Amanda130000NULL
Brandon90000130000
Carlita8000090000

SQL Question 8: Average Monthly Sales Per Product

Given a database of sales for Kraft Heinz, you are asked to determine the average number of sales per product on a monthly basis.

Please see below for the format of the table:

Example Input:

sale_iddate_saleproduct_idunits_sold
435201/03/2022018010
456301/10/2022018015
323101/15/2022894220
654302/06/202289425
879302/12/202201807
976203/03/2022018020
213203/10/2022894215

We want to find the average units sold for each product on a monthly basis.

Example Output:

monthproductavg_units_sold
1018012.5
1894220.0
201807.0
289425.0
3018020.0
3894215.0

Answer:


The above query uses the function to extract the month from the column. It then groups the data by product id and month, and finally computes the average units sold per grouping. The result is sorted by month then product for easier readability.

SQL Question 9: Sales Analysis with Customer Details

As a data analyst at Kraft Heinz, you are tasked to analyze the transaction amount for each customer and merge it with customer details. The table includes information on each transaction the company has processed and the table contains the details on each customer. Given the following data, write a SQL query to show the total monetary amount a customer has spent, joining both tables.

Example Input:

transaction_idcustomer_idamount_spent
1160.5
2295.7
3150.0
43200.3
5245.2

Example Input:

customer_idfirst_namelast_nameemail
1JohnDoejohn.doe@example.com
2JaneSmithjane.smith@example.com
3BobJohnsonbob.johnson@example.com

Answer:


This PostgreSQL query first joins the and tables on the column. Then, it groups by the customer details and sums the to get the total monetary amount each customer has spent.

Since join questions come up so often during SQL interviews, try this Snapchat Join SQL question:

Snapchat SQL Interview question using JOINS

How To Prepare for the Kraft Heinz SQL Interview

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. Beyond just solving the above Kraft Heinz SQL interview questions, you should also solve the 200+ DataLemur interview questions which come from companies like Netflix, Airbnb, and Amazon.

DataLemur Questions

Each exercise has multiple hints, step-by-step solutions and most importantly, there's an online SQL code editor so you can right online code up your SQL query answer and have it graded.

To prep for the Kraft Heinz SQL interview you can also be wise to solve SQL questions from other food and facilities companies like:

However, if your SQL coding skills are weak, don't worry about jumping right into solving questions – go learn SQL with this DataLemur SQL tutorial.

Free SQL tutorial

This tutorial covers things like filtering groups with HAVING and window functions – both of these come up often in Kraft Heinz SQL interviews.

Kraft Heinz Data Science Interview Tips

What Do Kraft Heinz Data Science Interviews Cover?

Beyond writing SQL queries, the other types of questions covered in the Kraft Heinz Data Science Interview are:

Kraft Heinz Data Scientist

How To Prepare for Kraft Heinz Data Science Interviews?

To prepare for Kraft Heinz Data Science interviews read the book Ace the Data Science Interview because it's got:

  • 201 interview questions sourced from tech companies like Netflix, Google, & Airbnb
  • a crash course covering Stats, ML, & Data Case Studies
  • over 1000+ reviews on Amazon & 4.5-star rating

Ace the Data Science Interview by Nick Singh Kevin Huo

Don't ignore the behavioral interview – prepare for that using this list of behavioral interview questions for Data Scientists.

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