SQL Deep Dive: 50 Job Interview Questions to Pro-Level Mastery! - Leetcode 1873 | Data Science

Welcome to the first episode of our groundbreaking series designed to take your SQL skills to the next level! In this series, we're tackling 50 of the most challenging and insightful interview questions on #advanced SQL, aimed at transforming you from an intermediate user to a bona fide #sql expert. Whether you're preparing for a job #interview , seeking to enhance your data manipulation capabilities, or simply passionate about mastering the complexities of SQL, this series is your ultimate roadmap.

SQL Schema:
Create table If Not Exists Employees (employee_id int, name varchar(30), salary int)
Truncate table Employees
insert into Employees (employee_id, name, salary) values ('2', 'Meir', '3000')
insert into Employees (employee_id, name, salary) values ('3', 'Michael', '3800')
insert into Employees (employee_id, name, salary) values ('7', 'Addilyn', '7400')
insert into Employees (employee_id, name, salary) values ('8', 'Juan', '6100')
insert into Employees (employee_id, name, salary) values ('9', 'Kannon', '7700')

Pandas Schema:
data = [[2, 'Meir', 3000], [3, 'Michael', 3800], [7, 'Addilyn', 7400], [8, 'Juan', 6100], [9, 'Kannon', 7700]]
employees = pd.DataFrame(data, columns=['employee_id', 'name', 'salary']).astype({'employee_id':'int64', 'name':'object', 'salary':'int64'})

In this first episode, we kick things off with a deep dive into a question that stumps many aspiring SQL professionals. We'll explore the intricacies of advanced query writing, focusing on techniques that go beyond the basics of SELECT statements and WHERE clauses. You'll learn about advanced joins, window functions, recursive queries, and much more.

What to Expect:

Detailed Explanations: We don't just solve the question; we dissect it. You'll understand not only the 'how' but also the 'why' behind each solution, ensuring you can apply these principles to a variety of SQL challenges.
Step-by-Step Approach: Our tutorials are designed to be easy to follow. We break down complex concepts into manageable parts, making advanced SQL more accessible than ever.
Real-World Applications: These aren't just theoretical exercises. Each question is selected for its relevance to real-world SQL problems, ensuring you gain practical skills that you can apply in a professional setting.
Interactive Learning: Engage with the content through quizzes and challenges presented throughout the series. Test your knowledge, practice new skills, and solidify your understanding of advanced SQL techniques.
Community Support: Join a growing community of SQL enthusiasts and professionals. Share insights, ask questions, and receive feedback through the comments section below each video.

Why This Series?

SQL remains one of the most in-demand skills in the tech industry, and for a good reason. It's the backbone of data analysis, database management, and many forms of programming. As data continues to drive decision-making in businesses worldwide, the ability to manipulate and retrieve data efficiently becomes increasingly valuable. This series is designed to equip you with these skills, ensuring you're not just ready for your next job interview but also prepared to tackle real-world data challenges.

Who Should Watch?

Intermediate SQL users looking to advance their skills.
Job seekers preparing for technical interviews.
Data professionals seeking to deepen their understanding of SQL.
Anyone with a passion for data and an eagerness to learn.
How to Get the Most Out of This Series:

Practice Along: Have your SQL environment ready to try out each question as we go through them.
Engage: Leave comments with your own solutions, questions, or insights.
Stay Consistent: Follow the series for a comprehensive understanding of advanced SQL.

Subscribe and Join Us on This Journey

Don't forget to subscribe and hit the bell icon so you won't miss any updates in this series. Each episode builds on the last, forming a comprehensive curriculum that will leave you well-versed in advanced SQL.

Let's embark on this journey together, transforming challenges into opportunities for growth and learning. Dive into the world of advanced SQL with us, and let's decode the secrets to becoming an SQL expert, one question at a time.

[srijitbhattacharya]

Select employee_id,
case when employee_id%2<>0 and name not like 'M%' then salary else 0 end as bonus
from
employeesx

[vijaygupta]

I try using same method but without if in MySQL

Select employee_id,
case when employee_id%2=1 and name not like 'M%' then salary else 0 end
as bonus from Employees

[williamlu]

SELECT employee_id, name, CASE WHEN
employee_id % 2 = 1 and LEFT(name, 1) <> 'M' THEN salary
ELSE 0 END AS bonus
FROM Employees ORDER BY employee_id;