At Las Vegas Sands, SQL is used to analyze customer gambling behaviors, helping them understand trends and preferences that can enhance the overall gaming experience. They also use SQL to manage gaming data and customer databases, allowing them to optimize casino operations and improve service delivery, which is why Las Vegas Sands asks SQL problems in interviews for Data Science, Analytics, and Data Engineering jobs.
SQL is utilized for analyzing customer gambling behaviors and optimizing casino operation efficiency, specifically by managing real-time gaming data and customer databases. For this reason Las Vegas Sands asks SQL problems in interviews for Data Science, Analytics, and & Data Engineering jobs.
So, to help you study, here’s 8 Las Vegas Sands SQL interview questions – able to answer them all?
Las Vegas Sands, a leading global developer of destination properties, takes customer loyalty very seriously. These properties incorporate accommodations, gaming, entertainment and retail, convention and exhibition facilities, celebrity chef restaurants and other amenities. Your task is to write a SQL query that will identify 'whale' users - these users are VIPs because they frequently book stays, attend shows, and dine at the restaurants. We have two tables and . Try to find users who have done more than 20 bookings and more than 50 restaurant visits in the year 2022.
booking_id | user_id | booking_date | num_rooms |
---|---|---|---|
1 | 123 | 01/05/2022 | 2 |
2 | 265 | 01/10/2022 | 1 |
3 | 362 | 02/18/2022 | 3 |
4 | 123 | 03/26/2022 | 4 |
5 | 981 | 04/05/2022 | 1 |
visit_id | user_id | visit_date |
---|---|---|
1 | 123 | 01/01/2022 |
2 | 265 | 01/10/2022 |
3 | 362 | 02/18/2022 |
4 | 123 | 02/26/2022 |
5 | 981 | 02/05/2022 |
This query joins the two tables and on the field, and then filters for users who have more than 20 bookings and more than 50 restaurant visits in the year 2022. The function is used to get the year part of the date. The function is used in the subquery to get the total number of bookings and restaurant visits for each user. The results are the user IDs of the VIP 'whale' customers.
To practice a similar customer analytics SQL question where you can code right in the browser and have your SQL solution instantly graded, try this Walmart Labs SQL Interview Question:
Imagine there was a table of Las Vegas Sands employee salaries, along with which department they were in. Write a query to compare the average salary of employees in each department to the company's average salary. 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.
Write a SQL query for this question directly within the browser on DataLemur:
The answer is LONG – 30+ lines of SQL. You can find a step-by-step solution here: Department vs. Company Salary.
Note: interviews at Las Vegas Sands 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 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 statement that are not returned by the second statement.
Here's a PostgreSQL example of using to find all of Las Vegas Sands' 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 operator instead of . The operator will return all rows, including duplicates.
We suppose at Las Vegas Sands Corporation you've been given their operational dataset for analysis. You're specifically interested in the revenue performance of their different casino properties over time.
Las Vegas Sands Corporation operates multiple resorts including The Venetian Resort and Sands Expo in Las Vegas, Marina Bay Sands Singapore and Venetian Macao, Sands Cotai Central etc.
Assume we have a table named where each row represents a daily revenue entry of a particular casino property.
The table has the following columns:
Write a SQL query to find the monthly revenue growth rate for each casino property from January 2022 to December 2022.
Assume that the growth rate can be calculated as follows:
growth_rate = (this_month_revenue - last_month_revenue) / last_month_revenue
revenue_id | property_id | date | amount_in_usd |
---|---|---|---|
1 | 1 | 2022-01-01 | 50000 |
2 | 1 | 2022-01-02 | 60000 |
3 | 1 | 2022-02-01 | 70000 |
4 | 1 | 2022-02-02 | 80000 |
5 | 1 | 2022-03-01 | 90000 |
6 | 2 | 2022-01-01 | 70000 |
7 | 2 | 2022-01-02 | 80000 |
8 | 2 | 2022-02-01 | 90000 |
9 | 2 | 2022-02-02 | 100000 |
10 | 2 | 2022-03-01 | 110000 |
Here is a possible PostgreSQL query that uses window functions to calculate the growth rate:
This query calculates the monthly total revenue and applies the formula for growth rate for each property and each month. It uses the function to access data of the previous row. The clause divides the data into separate blocks (for each property), and for each block, the function is applied.
To practice a similar window function interview problem which uses RANK() on DataLemur's free interactive coding environment, try this Amazon SQL Interview Question:
A cross-join, also known as a cartesian join, is a type of JOIN operation in SQL that creates a new table by combining each row from the first table with every row from the second table. This results in a table with a row for every possible combination of rows from the two input tables.
An example of when this might be useful is if you wanted to first make a dataset containing all possible pairs of customers and products data, in order to later build a Machine Learning model to predict the probability of a customer purchasing a particular product.
However, it is important to note that cross-joins can create very large tables, especially if the input tables have a large number of rows. For example, if you had 10,000 customers and 5,000 different product SKUs, the resulting cross-join would have 50 million rows.
The Las Vegas Sands Corporation is interested in analyzing its customer demographics for strategic planning. From their database, they would like to filter customers who reside in the USA, are over 25 years old and visited their casinos in 2022.
They would also like to know specifically how many of these customers are VIP members and how many are regular members. VIP members are identified by a membership status with value 1, while regular members have a value 0.
customer_id | name | age | country | last_visit | membership_status |
---|---|---|---|---|---|
1021 | Alex Smith | 30 | USA | 2022-06-25 | 1 |
2560 | Maria Garcia | 45 | Spain | 2022-01-03 | 0 |
1733 | John Doe | 28 | USA | 2022-03-12 | 0 |
9826 | Jane Lee | 26 | USA | 2021-12-15 | 1 |
6234 | Peter Green | 33 | USA | 2022-02-22 | 1 |
customer_id | name | membership_status |
---|---|---|
1021 | Alex Smith | 1 |
1733 | John Doe | 0 |
6234 | Peter Green | 1 |
In this SQL statement, we filter the records so that only the customers from the USA, who are over 25 years old, and visited the casinos in 2022 pass through. We then select their customer_id, their name, and their membership status. This provides a list of customers that the Las Vegas Sands Corporation needs for their strategic planning. It also divides these customers into VIP and regular members.
Both and are used to combine the results of two or more statements into a single result set.
However, only includes one instance of a duplicate, whereas includes duplicates.
Las Vegas Sands Corp. is a major developer of integrated resorts, which are hotels that include casinos, shopping malls, convention centers, and other amenities. Let's assume they recently ran a digital marketing campaign with the aim of increasing hotel reservations. They want to know the Click-Through Rate (CTR) of the ads. In digital marketing, the Click-Through Rate is the ratio of users who click on a specific link to the number of total users who view a page, email, or advertisement.
We'll need to know the number of times the ad was displayed to users () and how many times users clicked on the ad to make a reservation ().
Let's consider the following tables for this problem:
ad_id | display_date | impressions |
---|---|---|
7846 | 06/05/2022 00:00:00 | 1540 |
3927 | 06/10/2022 00:00:00 | 1206 |
8452 | 06/18/2022 00:00:00 | 1783 |
2365 | 06/26/2022 00:00:00 | 1375 |
5498 | 07/05/2022 00:00:00 | 1692 |
ad_id | click_date | clicks |
---|---|---|
7846 | 06/05/2022 00:00:00 | 752 |
3927 | 06/10/2022 00:00:00 | 632 |
8452 | 06/18/2022 00:00:00 | 945 |
2365 | 06/26/2022 00:00:00 | 789 |
5498 | 07/05/2022 00:00:00 | 845 |
We need to calculate the Click-Through Rate (CTR) for each ad, which is the number of clicks divided by the number of impressions.
This SQL query will join the and tables based on the and the date the ad was displayed. The calculation of the CTR is then made using the number of clicks (from the table) divided by the number of impressions (from the table), and multiplied by 100 to get the percentage. The is used to force PostgreSQL to perform a floating point division, as otherwise it would do an integer division.
To practice a similar SQL problem on DataLemur's free online SQL coding environment, attempt this Meta SQL interview question:
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 above Las Vegas Sands SQL interview questions, you should also solve the 200+ FAANG SQL Questions on DataLemur which come from companies like Google, Microsoft and Silicon Valley startups.
Each SQL question has multiple hints, step-by-step solutions and most importantly, there's an online SQL coding environment so you can instantly run your SQL query answer and have it graded.
To prep for the Las Vegas Sands SQL interview it is also wise to solve SQL questions from other hospitality and restaurant companies like:
However, if your SQL skills are weak, forget about jumping right into solving questions – improve your SQL foundations with this SQL tutorial for Data Analytics.
This tutorial covers things like handling missing data (NULLs) and manipulating string/text data – both of these show up routinely in SQL interviews at Las Vegas Sands.
In addition to SQL interview questions, the other types of problems to prepare for the Las Vegas Sands Data Science Interview are:
To prepare for the Las Vegas Sands Data Science interview make sure you have a firm understanding of the company's values and mission – this will be clutch for acing the behavioral interview. For technical interviews prepare by reading Ace the Data Science Interview. The book's got: