10 Covetrus SQL Interview Questions (Updated 2024)

Covetrus employees use SQL daily to analyze pet health data, extracting valuable insights that help improve veterinary care and treatment options. They also manage customer databases with SQL to create personalized marketing strategies that resonate with pet owners and veterinary practices, which is why Covetrus includes SQL problems during interviews for Data Science, Analytics, and Data Engineering jobs.

So, to help you prepare for the Covetrus SQL interview, here's 10 Covetrus SQL interview questions in this blog.

10 Covetrus SQL Interview Questions

SQL Question 1: Identify the top VIP customers for Covetrus

Covetrus is a global, technology-enabled animal health business offering a comprehensive service and technology platform. The activity we will focus on for identifying VIP users is purchasing products. Write a SQL query to identify the top 10 customers who purchased most frequently in the last six months. The frequency of purchases is the dividing of the count of orders for each customer by the duration (in months) from their first to their last purchase within six months.

Example Input:

Example Input:

You need to include the following information in the output:

Answer:

This query first calculates the total orders and the duration of the purchases for all the customers using the window functions in the CTE (Common Table Expression) . The main query then calculates the purchase frequency as the ratio of total orders and duration. It then orders the customers in the descending order of purchase frequency to get the top VIP customers. Note that customers with a duration of zero (i.e., those who only made one purchase) will get a NaN frequency, which may rank higher than any real frequencies. If this is an issue, you could add a CASE statement to replace these with zero or a predetermined maximum/minimum value.

To solve a related super-user data analysis question on DataLemur's free interactive SQL code editor, try this Microsoft Teams Power User SQL Interview Question:

Discover Covetrus' groundbreaking veterinary operating system that is set to transform the way veterinary practices operate! Understanding Covetrus' innovative solutions can give you a glimpse into how technology is enhancing the veterinary field.

SQL Question 2: Top Three Salaries

Suppose there was a table of Covetrus employee salary data. Write a SQL query to find the top three highest paid employees in each department.

Covetrus Example Input:

Example Input:

Example Output:

Solve this interview question and run your code right in DataLemur's online SQL environment:

Answer:

We use the DENSE_RANK() window function to generate unique ranks for each employee's salary within their department, with higher salaries receiving lower ranks. Then, we wrap this up in a CTE and filter the employees with a ranking of 3 or lower.

If the code above is tough, you can find a detailed solution here: Top 3 Department Salaries.

SQL Question 3: Can you describe the role of the constraint and provide an example of a situation where it might be applied?

The constraint is used to specify a condition that the data in a column must meet. If a row is inserted or updated and the data in the column doesn't meet the condition specified by the constraint, the operation will sadly fail.

For example, you might use a constraint to ensure that a column contains only positive numbers, or that a date is within a certain range.

For example, if you had a table of Covetrus employees, here's an example of how to use the constraint in a statement:

SQL Question 4: Product sales trend analysis

As an analyst at Covetrus, a global animal-health technology and services company, one of your initial assignments is to provide monthly analysis of product sales. You are given a table that contains one row for each product sale. Each row includes the product id, sale date and the units sold.

Write a SQL query that computes the rolling 3-month average unit sales, for each product, on a monthly basis. Return the results ordered by product and month. The comparison should be done exactly on a rolling 3-month basis that is from start of month 1 to the end of month 3.

Please assume the sales table is as follows:

Example Input:

Expected output:

Answer:

Here is a PostgreSQL query that would solve the problem:

This query partitions the sales dataset by the and then orders this partitioned data by the . It takes a rolling average of over a window of the current month and the two preceding months for each row in the partitioned data.

The function is used to round the down to the nearest month. The function is used with a window function to create a rolling average. The clause sets the window for the average calculation- current month and two preceding months. The results are then ordered by and .

For more window function practice, solve this Uber SQL problem on DataLemur's interactive SQL code editor:

SQL Question 5: What does it mean to perform a self-join?

A self-join is a type of where a table is joined to itself. To execute a self-join, you must include the table name twice in the clause and assign a different alias to each instance. You can then join the two copies of the table using a clause, and use a clause to specify the relationship between the rows.

For instance, suppose you had website visitor data for Covetrus, exported from the company's Google Analytics account. To assist the web-dev team, you needed to analyze pairs of pages for UX or navigational issues. As part of that analysis, you wanted to generate all pairs of URLs, but needed to exclude pairs where both URLs were the same since that is not a valid pair.

You could use the following self-join:

This query returns the url of each page () along with the url of the page that referred to it (). The self-join is performed using the field, which specifies the id of the page that referred the visitor to the current page, and avoids any pages that referred themself (aka data anomalies).

SQL Question 6: Filter Customer Records by Various Conditions

Covetrus is a company that provides a wide range of services to veterinary professionals including pharmaceuticals, software, and diagnostic tools. In order to target marketing and improvements, it needs to identify various customer groups.

You're given a table that contains detailed customer data. Your task is to write a SQL query to return all customers who are either under 30 or over 60 years old, live in New York and purchased at least one service in the past year. Assume that the table has a column that shows the date of the last service purchase.

Example Input:

Example Output:

Answer:

Here's a query that solves the problem using the clause in combination with and operators:

This query first checks whether a customer is either under the age of 30 or over the age of 60. Then it checks if the customer lives in New York. Finally, it checks if the customer has purchased at least one service in the past year by comparing the to a manually entered date January 01, 2021. If all these conditions are met, the of the customer is returned.

SQL Question 7: What do the / operators do, and can you give an example?

For a tangible example of in PostgreSQL, suppose you were doing an HR Analytics project for Covetrus, and had access to Covetrus's contractors and employees data. Assume that some employees were previously contractors, and vice versa, and thus would show up in both tables.

You could use operator to find all contractors who never were a employee using this query:

Note that is available in PostgreSQL and SQL Server, while is the equivalent operator which is available in MySQL and Oracle (but don't worry about knowing which RDBMS supports which exact commands since Covetrus interviewers aren't trying to trip you up on memorizing SQL syntax).

SQL Question 8: Compute Average Sales Per Month for Each Product

As part of a data analyst role at Covetrus, a company specializing in animal health technology and services, you are tasked with acquiring insightsfrom the following table. This table documents sales records for various products throughout the month. Write an SQL Query to calculate the average sales per product per month.

Example Input:

Example Output:

Answer:

In the query above, we extract the month from using the function. We then group by both the month as well as the and calculate the average sale for each group. The average sale is calculated by multiplying the by . We also sort the result by and .

SQL Question 9: Filtering Customer Records at Covetrus

Covetrus, a global animal-health technology and services company dedicated to advancing the world of veterinary medicine, maintains a detailed record of their customer interactions. One key database is the which contains information about customer calls and the reason for contact.

During monthly reports, the team typically filters the database to find the pattern 'medication' within the content field of any contact record. The purpose of this activity is to analyze how many customer interactions are related to medication queries.

Can you write the PostgreSQL query that would retrieve all records in the table where the field contains the word 'medication'?

Example Input:

Example Output:

Answer:

This SQL query uses the keyword in clause to filter all records where the contains the word 'medication'. The symbol is a wildcard character that matches any sequence of characters. So, '%medication%' will match any field that contains the word 'medication' anywhere in its content.

SQL Question 10: What do stored procedures do?

Stored procedures in SQL are like recipes in a cookbook. Just like a recipe tells you the ingredients and instructions for making a particular dish, a stored procedure tells the DBMS the logic/statements needed to perform a specific task. Just like you can use a recipe to make the same dish over and over again, you can use a stored procedure to repeat the same task multiple times with different input parameters (which is why stored procedures are so damn useful!).

Say you were a Data Analyst working on a HR analytics project. A common sub-task you might have to do is calculate the average salary for a given department at Covetrus, which would be perfect for a stored procedure:

To call this stored procedure and find the average salary for the Data Science department you'd execute a query like this:

Preparing For The Covetrus SQL Interview

The key to acing a Covetrus SQL interview is to practice, practice, and then practice some more! Besides solving the earlier Covetrus SQL interview questions, you should also solve the 200+ DataLemur SQL Interview Questions which come from companies like tech companies and healthcare and pharmaceutical companies like Covetrus.

Each exercise has multiple hints, detailed solutions and most importantly, there is an interactive coding environment so you can right in the browser run your query and have it checked.

To prep for the Covetrus SQL interview you can also be helpful to practice interview questions from other healthcare and pharmaceutical companies like:

• Elanco Animal Health SQL questions
• PerkinElmer SQL questions
• Encompass Health SQL questions
• Syneos Health SQL questions

But if your SQL query skills are weak, forget about going right into solving questions – refresh your SQL knowledge with this DataLemur SQL tutorial.

This tutorial covers SQL topics like joining a table to itself and transforming strings with CONCAT()/LOWER()/TRIM() – both of which pop up routinely in Covetrus SQL assessments.

Covetrus Data Science Interview Tips

What Do Covetrus Data Science Interviews Cover?

Besides SQL interview questions, the other types of questions to prepare for the Covetrus Data Science Interview include:

• Statistics & AB Testing Questions
• Coding Questions in Python or R
• Product Data Science Interview Questions
• ML Modelling Questions
• Behavioral Interview Questions focussed on Covetrus culture and values

How To Prepare for Covetrus Data Science Interviews?

To prepare for Covetrus 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 covering Python, SQL & ML
• over 1000+ reviews on Amazon & 4.5-star rating

Don't ignore the behavioral interview – prep for it using this behavioral interview question bank.