# 8 Host Hotels & Resorts SQL Interview Questions (Updated 2024)

Updated on

June 30, 2024

At Host Hotels & Resorts, SQL is used across the company for analyzing guest booking patterns and optimizing room price strategies. That's the reason behind why Host Hotels & Resorts almost always evaluates jobseekers on SQL coding questions during interviews for Data Science, Data Engineering and Data Analytics jobs.

As such, to help you prep for the Host Hotels & Resorts SQL interview, here’s 8 Host Hotels & Resorts SQL interview questions in this blog.

## 8 Host Hotels & Resorts SQL Interview Questions

### SQL Question 1: Identifying VIP customers at Host Hotels & Resorts

For the company "Host Hotels & Resorts", a VIP customer (whale user) could be defined as a customer who frequently books rooms at high spending costs, indicating a strong loyalty towards the hotel chain. Can you write a SQL query to identify such power users based on the frequency of their bookings and the total spending in a given year (e.g., 2022)?

##### Example Input:
booking_idcustomer_idbooking_dateroom_typespending
1001101/10/2022Deluxe Room500
1002201/18/2022Suite Room1000
1003102/15/2022Executive Room700
1004303/12/2022Deluxe Room500
1005103/20/2022Suite Room1000
1006404/15/2022Deluxe Room500
##### Example Output:
customer_idbooking_frequencytotal_spending
132200

This query selects the , counts the number of bookings made (i.e., booking_frequency) and sums the total spending for each customer in the year 2022. The clause filters only those customers who had more than one booking and spent over \$500 in total. The resulting list is sorted by booking frequency and total spending, both in descending order, which gives us the most important customers for Host Hotels & Resorts.

To practice a similar power-user data analysis problem question on DataLemur's free online SQL coding environment, try this Microsoft Teams Power User SQL Interview Question:

### SQL Question 2: Department Salaries

Suppose there was a table of Host Hotels & Resorts 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 interview question interactively on DataLemur:

The solution is LONG – 30+ lines of SQL. You can find a step-by-step solution with hints here: Department Salaries.

Read about Host Hotels & Resorts corporate strategy to help prep for the interview!

### SQL Question 3: Can you give an example of a one-to-one relationship between two entities, vs. a one-to-many relationship?

In database schema design, a one-to-one relationship is when each entity is associated with only one instance of the other. For instance, a US citizen's relationship with their social-security number (SSN) is one-to-one because each citizen can only have one SSN, and each SSN belongs to one person.

A one-to-many relationship, on the other hand, is when one entity can be associated with multiple instances of the other entity. An example of this is the relationship between a person and their email addresses - one person can have multiple email addresses, but each email address only belongs to one person.

### SQL Question 4: Analyze Hotel Bookings

Given the and tables below, write a SQL query to determine the total revenue and average room rate per hotel per quarter. The table contains information about each booking such as the hotel id, the room rate, booking date etc. while the table contains information about each hotel such as the hotel id, name and location.

Assume that the room_rate is inclusive of all nights a guest stays (i.e., if a guest booked a hotel for three nights at a rate of $300, the room_rate column would show$300).

##### Example Input:
booking_idhotel_idbooking_dateroom_rate
12002022-01-10200
22002022-02-15180
33002022-01-20250
43002022-04-18280
54002022-05-05325
64002022-03-12295
74002022-07-19350
85002022-02-14225
95002022-05-22275
105002022-11-02290
##### Example Input:
hotel_idnamelocation
200HHR WashingtonWashington
300HHR San DiegoSan Diego
400HHR ManhattanNew York
500HHR OrlandoOrlando

The above query will join the bookings and hotels tables on . It will then group by the hotel name, location and the quarter of the booking date (extracted using the function). Under each grouping, it calculates the total revenue (sum of all room rates) and the average room rate. The result is then ordered by hotel name and quarter.

For more window function practice, try this Uber SQL Interview Question on DataLemur's online SQL code editor:

### SQL Question 5: What's the difference between relational and non-relational databases?

While both types of databases are used to store data (no duh!), relational databases and non-relational (also known as NoSQL databases) differ in a few important ways:

Data model: Relational databases use a data model consisting of tables and rows, while NoSQL databases use a variety of data models, including document, key-value, columnar, and graph storage formats.

Data integrity: Relational databases use structured query language (SQL) and enforce strict data integrity rules through the use of foreign keys and transactions. NoSQL databases may not use SQL and may have more relaxed data integrity rules.

Structure: Relational databases store data in a fixed, structured format, while NoSQL databases allow for more flexibility in terms of data structure.

ACID compliance: Relational databases are typically into shrooms and are ACID-compliant (atomic, consistent, isolated, and durable), while NoSQL databases may not be fully ACID-compliant (but they try their best... and it's effort that counts...or at least that's what my gym teacher told me!)

### SQL Question 6: Booking and Room Occupancy Rates for Host Hotels & Resorts

Host Hotels & Resorts wants to understand room reservation and occupancy rates across their portfolio. As an SQL querying expert, they have asked you to create a suitable database design and perform a specific kind of analysis.

Specifically, they would like to know:

1. How many rooms are booked per hotel per day?
2. What is the daily occupancy rate for each hotel?

For this analysis, consider the following entities:

• Hotels: Assume each hotel is uniquely identified by its .
• Rooms: Each room in a hotel has a unique and is associated with a specific .
• Bookings: Each booking is uniquely identified by a . Booking data includes the , , the , and .
##### Example Input:
hotel_idhotel_nametotal_rooms
1Host Hotel A100
2Host Hotel B50
room_idhotel_id
11
21
......
1001
1012
......
1502
##### Example Input:
booking_idhotel_idroom_idcheck_in_datecheck_out_date
1112022-01-012022-01-04
2122022-01-022022-01-05
3132022-01-012022-01-03
421012022-01-012022-01-02

Expected output for the date '2022-01-01' is as follows:

##### Example Output:
hotel_idbooked_roomstotal_roomsoccupancy_rate
131003.00%
21502.00%

To solve the problem, you can make use of PostgreSQL's built-in range type and generate_series function to create all the dates within the booking range.

In this query, we first create a series of dates within the year 2022. Then, we select all dates that fall in between the check-in and check-out dates for each booking (including both endpoints). Finally, we count the number of booked rooms, calculate the occupancy rate, and return the hotel ID, the total number of booked rooms, total room count, and the occupancy rate per hotel for '2022-01-01'.

### SQL Question 7: Can you explain the purpose of UNION?

is used to combine the results of multiple statements into a single result set.

Suppose you were doing an HR Analytics project for Host Hotels & Resorts, and needed to analyze both Host Hotels & Resorts's contractors and employees. You could use in the following way:

This statement would return a combined result set of Host Hotels & Resorts contractors and employees who were hired after the start of the year 2023.

### SQL Question 8: Average Occupancy Rate per Hotel

As a data analyst at Host Hotels & Resorts, you've been asked to find out the average occupancy rate per hotel for a given year. The occupancy rate is calculated as the total number of rooms occupied divided by the total number of rooms available.

Assume you have access to two tables: and . The table contains details about each hotel including the total number of rooms while the table contains a row for each booking made, indicating the hotel ID and the number of rooms booked for that particular booking.

#### Example Input:

hotel_idhotel_nametotal_rooms
1"Host Hotel Bay Area"500
2"Host Hotel Sacramento"400
3"Host Hotel Seattle"600

#### Example Input:

booking_idhotel_iddaterooms_booked
101101/05/2022200
102101/14/2022150
103201/20/2022300
104201/30/2022250
105301/05/2022400
106301/20/2022380

#### Example Output:

hotel_idavg_occupancy_rate
10.70
20.65
30.65

In this query, we first join the and tables on the . Then, we filter the bookings for the given year using the function. For each hotel, we calculate the average occupancy rate by dividing the number of rooms booked by the total number of rooms, ensuring decimals are preserved by multiplying the numerator with 1.0. We then group by to get the average for each hotel.

To practice a very similar question try this interactive Amazon Highest-Grossing Items Question which is similar for calculating a rate based on 2 columns or this Facebook Advertiser Status Question which is similar for <dealing with business calculations.

### Host Hotels & Resorts SQL Interview Tips

The key to acing a Host Hotels & Resorts SQL interview is to practice, practice, and then practice some more! Beyond just solving the above Host Hotels & Resorts SQL interview questions, you should also solve the 200+ FAANG SQL Questions on DataLemur which come from companies like Facebook, Google, and VC-backed startups.

Each exercise has hints to guide you, step-by-step solutions and best of all, there is an online SQL coding environment so you can right in the browser run your SQL query and have it executed.

To prep for the Host Hotels & Resorts SQL interview you can also be wise to practice SQL questions from other real estate and REIT companies like:

However, if your SQL skills are weak, don't worry about going right into solving questions – improve your SQL foundations with this free SQL tutorial.

This tutorial covers SQL topics like LEFT vs. RIGHT JOIN and handling timestamps – both of which come up routinely during Host Hotels & Resorts interviews.

### Host Hotels & Resorts Data Science Interview Tips

#### What Do Host Hotels & Resorts Data Science Interviews Cover?

In addition to SQL query questions, the other question categories tested in the Host Hotels & Resorts Data Science Interview are:

#### How To Prepare for Host Hotels & Resorts Data Science Interviews?

To prepare for Host Hotels & Resorts Data Science interviews read the book Ace the Data Science Interview because it's got:

• 201 interview questions taken from FAANG tech companies
• a refresher on SQL, Product-Sense & ML
• over 1000+ reviews on Amazon & 4.5-star rating