Linkedin Interview Questions (7+ Questions)

SQL Interview Question: Listing Customers Who Have Never Placed an Order

Objective

Construct an SQL query to identify and list the names of all customers who have never placed an order. Ensure the resulting list is ordered alphabetically by the customers' names.

Additional Information

You are provided with two tables:

• customers

  • customer_id (integer): Unique identifier for each customer.
  • customer_name (string): Name of the customer.

• orders

  • order_id (integer): Unique identifier for each order.
  • customer_id (integer): Identifier linking the order to a customer.
  • order_date (date): The date on which the order was placed.

Your query should return a table with a single column, customer_name, containing the names of customers who have no corresponding entries in the orders table. If every customer has placed at least one order, the query should return an empty result set.

Example SQL Query

SELECT customer_name
FROM customers
WHERE customer_id NOT IN (SELECT DISTINCT customer_id FROM orders)
ORDER BY customer_name;

This query effectively lists the names of all customers who have never placed an order by filtering out the customer_ids found in the orders table. The resulting list is then ordered alphabetically by the customer_name to ensure clarity and easy navigation.

Detailed Explanation for SQL Query to Retrieve Customer Names, Total Spending, and Customer Tier

In the context of SQL interview questions, a commonly asked problem involves retrieving customer names along with their total spending and classifying them into different tiers based on their spendi...

🔒 Premium Content

Detailed explanation and solution available for premium members.

Upgrade to Premium →

How to Calculate Yearly Total Sales, Previous Year's Total Sales, and Sales Growth Percentage with SQL

When you're faced with the task of calculating yearly total sales, the previous year's sales, and the growth percentage in SQL, it's essential to use efficient querying techniques to achieve a...

🔒 Premium Content

Detailed explanation and solution available for premium members.

Upgrade to Premium →

SELECT
candidate_id
FROM
candidates
WHERE
skill IN ('Python', 'Tableau', 'PostgreSQL')
GROUP BY
candidate_id
HAVING
COUNT(DISTINCT skill) = 3
ORDER BY
candidate_id ASC;

SELECT
COUNT(DISTINCT company_id) AS duplicate_companies
FROM
(
SELECT
company_id,
title,
description
FROM
job_listings
GROUP BY
company_id,
title,
description
HAVING
COUNT(job_id) > 1
) AS duplicates;

Airbnb hosts over 6 million listings across 220+ countries with 150 million users. QA testing of property booking APIs requires comprehensive validation of search algorithms, availability checking, booking workflows, and review systems to ensure seamless travel experiences....

🔒 Premium Content

Detailed explanation and solution available for premium members.

Upgrade to Premium →

Stripe is a leading payment processing platform handling billions of transactions. QA testing of payment APIs requires comprehensive validation of endpoints, status codes, response times, and data integrity to ensure secure and reliable financial transactions....

🔒 Premium Content

Detailed explanation and solution available for premium members.

Upgrade to Premium →