10 Darden Restaurants SQL Interview Questions (Updated 2024)
At Darden Restaurants, SQL is used to analyze customer preferences and dining habits, helping them customize menus and enhance the overall dining experience. They also rely on SQL to manage supply chain data, ensuring they have the right amount of food on hand to meet customer demand, that is why Darden Restaurants tests SQL query questions during interviews for Data Science, Analytics, and Data Engineering jobs.
To help you prep for the Darden Restaurants SQL interview, we've collected 10 Darden Restaurants SQL interview questions – can you solve them?
10 Darden Restaurants SQL Interview Questions
SQL Question 1: Identify Power Users Based on Restaurant Visits and Spend
As a data analyst for Darden Restaurants, your task is to identify the power users, defined as those guests that visit the restaurant more often and spend the most. Write a SQL query using the customer and transaction tables below to find the top 5 power users in the month of August.
Sample Input:
|
| customer_id | first_name | last_name | |
|---|---|---|---|
| 123 | John | Doe | jdoe@gmail.com |
| 265 | Jane | Smith | jsmith@gmail.com |
| 362 | Marc | Brown | mbrown@gmail.com |
| 192 | Emily | Stewart | estewart@gmail.com |
| 981 | Michael | Johnson | mjohnson@gmail.com |
Sample Input:
| transaction_id | customer_id | transaction_date | spend |
|---|---|---|---|
| 6171 | 123 | 08/10/2022 | 50.00 |
| 7802 | 123 | 08/15/2022 | 45.00 |
| 5293 | 265 | 08/20/2022 | 65.00 |
| 6352 | 192 | 08/25/2022 | 70.00 |
| 4517 | 981 | 08/30/2022 | 30.00 |
| 7890 | 123 | 08/20/2022 | 55.00 |
| 6821 | 192 | 08/15/2022 | 60.00 |
Answer:
This query joins the and tables on the . It then selects the , , , total , and total . The clause filters the transactions happening in August 2022. It then groups by , , and . Finally, it orders by and in descending order and limits the result to the top 5 power users.
To practice a similar power-user data analysis problem question on DataLemur's free interactive coding environment, try this recently asked Microsoft SQL interview question:
Dive into Darden Restaurant's news to learn about their recent achievements and strategic initiatives that are driving growth in the restaurant sector! Understanding Darden's progress can provide valuable insights into how they are navigating the challenges of the dining landscape.
SQL Question 2: Department Salaries
You're given a table of Darden Restaurants employee and department salary data. Write a SQL query to find departments where the departments average salary is higher than the company's average salary.
You can solve this problem interactively on DataLemur:
The answer is LONG – 30+ lines of SQL. You can find a step-by-step solution here: Department vs. Company Salary.
SQL Question 3: What do foreign key's do?
A foreign key is a column or group of columns in a table that refers to the primary key in another table. The foreign key constraint helps maintain referential integrity between the two tables.
Let's examine employee data from Darden Restaurants's HR database:
:
| employee_id | first_name | last_name | manager_id |
|---|---|---|---|
| 1 | Aubrey | Graham | 3 |
| 2 | Marshal | Mathers | 3 |
| 3 | Dwayne | Carter | 4 |
| 4 | Shawn | Carter |
In this table, serves as the primary key and functions as a foreign key because it links to the of the employee's manager. This establishes a relationship between Darden Restaurants employees and their managers, allowing for easy querying to find an employee's manager or see which employees report to a specific manager.
The table may also have multiple foreign keys that reference primary keys in other tables. For example, and foreign keys could be used to connect each employee to their respective department and location.
SQL Question 4: Analyzing Monthly Sales Performance
Suppose Darden Restaurants wants to analyze the monthly performance of their different restaurant branches. For this, they have a table which records the revenues from each branch on a daily basis.
You are tasked to write a SQL query to calculate the running total of sales for each branch on a monthly basis, from the start of the year to the current month.
The table is as follows:
Example Input:
| id | branch_id | date | revenue |
|---|---|---|---|
| 1 | B001 | 01/02/2022 | 5000 |
| 2 | B002 | 01/04/2022 | 3000 |
| 3 | B001 | 01/05/2022 | 2000 |
| 4 | B001 | 02/04/2022 | 5500 |
| 5 | B002 | 02/18/2022 | 3500 |
| 6 | B001 | 03/04/2022 | 4000 |
| 7 | B002 | 03/10/2022 | 2500 |
Your result should present the running total of sales for each branch, for each month with the following format:
Example Output:
| branch_id | month | running_total |
|---|---|---|
| B001 | 1 | 7000 |
| B001 | 2 | 12500 |
| B001 | 3 | 16500 |
| B002 | 1 | 3000 |
| B002 | 2 | 6500 |
| B002 | 3 | 9000 |
Answer:
To calculate the running total on a monthly basis, we can use the window function with the clause partitioned by and ordered by .
In this query, we partition the data by and order it by . The function then computes the running total revenue with respect to the current row and all preceding rows within the same partition, providing the cumulative sales for each branch on a monthly basis.
For more window function practice, try this Uber SQL problem within DataLemur's online SQL coding environment:
SQL Question 5: When doing database schema design, what's an example of two entities that have a one-to-one relationship? What about one-to-many relationship?
In database schema design, a one-to-one relationship between two entities means that each entity is linked to a single instance of the other. For example, the relationship between a car and a license plate is one-to-one because each car has only one license plate, and each license plate belongs to one car.
In contrast, a one-to-many relationship is when one entity can be associated with multiple instances of the other entity. An example of this is the relationship between a teacher and their classes - a teacher can teach multiple classes, but each class is only associated with one teacher.
SQL Question 6: Darden Restaurants Customer Filtering
Assume you are a data analyst at Darden Restaurants group. You are given the task of identifying a certain segment of customers from the database who visited one of their restaurants in the last quarter, in the states of Florida or California, and have spent more than $150.
The filtering should be based on three conditions:
- They should have dined in the last quarter.
- They should have dined in either Florida or California.
- They should have spent more than $150.
Use the and tables for your analysis.
table:
| customer_id | first_name | last_name | state |
|---|---|---|---|
| 101 | John | Doe | Florida |
| 102 | Jane | Doe | California |
| 103 | Alex | Brown | New York |
| 104 | Alice | Smith | Florida |
table:
| transaction_id | customer_id | amount | transaction_date |
|---|---|---|---|
| 20101 | 101 | 200 | 2021-11-11 |
| 20202 | 101 | 120 | 2021-12-19 |
| 20303 | 102 | 90 | 2022-03-23 |
| 20404 | 103 | 160 | 2022-02-11 |
| 20505 | 104 | 80 | 2022-03-08 |
Answer:
With this query, we are joining the customers with their transactions and applying the conditions as specified in the problem. The function is used to get the date of the start of the current quarter, and we subtract 3 months from it to get the start date of the last quarter. We check if the transaction occurred after this date. We also filter based on the state (Florida or California) and the transaction amount (greater than $150). The result will be the list of customers who fit these criteria.
SQL Question 7: What is the difference between a primary key and a foreign key?
To explain the difference between a primary key and foreign key, let's start with an example Darden Restaurants sales database:
:
| 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, could be a primary key. It is unique for each row in the table and cannot contain null values.
and could both be foreign keys. They reference the primary keys of other tables, such as a table and a table, respectively. This establishes a relationship between the table and the other tables, such that each row in the sales database corresponds to a specific product and a specific customer.
SQL Question 8: Find Customers from Specific City
As part of the customer analytics at Darden Restaurants, you have been given access to the table which consist of customers' details. Write a SQL query to find the customers who are located in the city "Orlando".
Example Input:
| customer_id | first_name | last_name | email_id | city |
|---|---|---|---|---|
| 1 | John | Doe | john.doe@example.com | Orlando |
| 2 | Jenny | Smith | jenny.smith@example.com | New York |
| 3 | Sam | Brown | sam.brown@example.com | Orlando |
| 4 | Emily | Johnson | emily.johnson@example.com | San Francisco |
| 5 | Michael | Williams | michael.williams@example.com | Orlando |
Answer:
This query would return all records in the table where the attribute is like "Orlando". With this, we can get the list of customers based out in Orlando.
SQL Question 9: Analyze customer demographics and join that with restaurant locations.
In Darden Restaurants' database, there are two tables named and . The table consists of customers' information, including , , , , and . Meanwhile, the table has information about each of the restaurants, such as , , and .
Find the average age of customers for each restaurant location, presented sorted by descending order of average age.
Example Input:
| id | name | age | gender | favorite_restaurant_id |
|---|---|---|---|---|
| 1 | John | 45 | M | 3 |
| 2 | Linda | 34 | F | 1 |
| 3 | Robert | 56 | M | 2 |
| 4 | Laura | 19 | F | 1 |
| 5 | Mike | 32 | M | 2 |
Example Input:
| id | restaurant_name | location |
|---|---|---|
| 1 | Olive Garden | New York |
| 2 | LongHorn Steakhouse | Chicago |
| 3 | Bahama Breeze | Los Angeles |
Example Output:
| location | avg_age |
|---|---|
| Los Angeles | 45.00 |
| Chicago | 44.00 |
| New York | 26.50 |
Answer:
This query first joins the customers table with the restaurants table, linking them on the favorite restaurant id of the customers and the id of the restaurants. Then, it groups the data based on the location of restaurants and calculates the average age for each location. Finally, it presents the output sorted by average age in descending order. This query will help analyze the average customer age per restaurant location, which can be insightful for marking and business strategies.
Since join questions come up so often during SQL interviews, try this Snapchat JOIN SQL interview question:
SQL Question 10: What are the various types of joins used in SQL?
Joins in SQL allow you to combine data from different tables based on a shared key or set of keys.
Four JOIN types are available in SQL. For an example of each one, say you had sales data exported from Darden Restaurants's Salesforce CRM stored in a PostgreSQL database, and had access to two tables: and .
-
INNER JOIN: Retrieves rows from both tables where there is a match in the shared key or keys. For example, an between the table and the table would retrieve only the rows where the in the table matches the in the table.
-
LEFT JOIN: Retrieves all rows from the left table (in this case, the table) and any matching rows from the right table (the table). If there is no match in the right table, values will be returned for the right table's columns.
-
RIGHT JOIN: Retrieves all rows from the right table (in this case, the table) and any matching rows from the left table (the table). If there is no match in the left table, values will be returned for the left table's columns.
-
FULL OUTER JOIN: Retrieves all rows from both tables, regardless of whether there is a match in the shared key or keys. If there is no match, values will be returned for the columns of the non-matching table.
How To Prepare for the Darden Restaurants 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. Besides solving the earlier Darden Restaurants SQL interview questions, you should also solve the 200+ SQL exercises on DataLemur which come from companies like FAANG tech companies and tech startups.
Each exercise has hints to guide you, full answers and most importantly, there's an interactive SQL code editor so you can right in the browser run your SQL query and have it executed.
To prep for the Darden Restaurants SQL interview it is also a great idea to solve SQL problems from other hospitality and restaurant companies like:
- Chipotle SQL questions
- Bloomin' Brands SQL questions
- McDonald's SQL questions
- Texas Roadhouse SQL questions
But if your SQL coding skills are weak, forget about diving straight into solving questions – refresh your SQL knowledge with this interactive SQL tutorial.
This tutorial covers topics including creating summary stats with GROUP BY and UNION – both of which pop up frequently in Darden Restaurants SQL assessments.
Darden Restaurants Data Science Interview Tips
What Do Darden Restaurants Data Science Interviews Cover?
In addition to SQL interview questions, the other topics to practice for the Darden Restaurants Data Science Interview are:
- Probability & Stats Questions
- Coding Questions in Python or R
- Product-Sense Questions
- ML Interview Questions
- Behavioral Questions focussed on Darden Restaurants values & principles
How To Prepare for Darden Restaurants Data Science Interviews?
To prepare for Darden Restaurants Data Science interviews read the book Ace the Data Science Interview because it's got:
- 201 interview questions sourced from Facebook, Google & startups
- a crash course covering Python, SQL & ML
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Also focus on the behavioral interview – prep for that using this list of common Data Scientist behavioral interview questions.