Most stressful parts of coding interview

Source: hired.com

How Query is Executed

Order of SQL query execution is not the same as order query is written.
You probably noticed that when you write SELECT count(*) AS column_name, you can't use that column_name in WHERE or GROUP BY clause. It's because select clause in which you defined your alias is not executed yet!

Each query begins with finding the data that we need in a database, and then filtering that data down into something that can be processed and understood as quickly as possible. Because each part of the query is executed sequentially, it's important to understand the order of execution so that you know what results are accessible where.

In general, SQL queries are executed in the following order:

1. FROM: The first step is to identify the tables or views involved in the query. This is specified in the FROM clause of the query.

2. JOIN: If the query involves multiple tables and requires a join operation, the join conditions are evaluated to combine the data from different tables.

3. WHERE: The WHERE clause is applied to filter the rows based on specified conditions. Rows that do not meet the conditions are eliminated from further processing.

4. GROUP BY: If the query includes a GROUP BY clause, the rows are grouped based on the specified columns.

5. HAVING: If a HAVING clause is present, it is applied to filter the groups generated by the GROUP BY clause. Groups that do not meet the conditions are eliminated.

6. SELECT: The SELECT clause is applied to determine the columns to be included in the result set. Any calculations or functions specified in the SELECT clause are also evaluated at this stage.

7. DISTINCT: If the query includes the DISTINCT keyword, duplicate rows are removed from the result set.

8. ORDER BY: If an ORDER BY clause is present, the result set is sorted based on the specified columns.

9. LIMIT/OFFSET: If the query includes a LIMIT and/or OFFSET clause, the result set is limited to a specific number of rows and/or skipped by a certain number of rows.

It’s important to note that not all queries will include every step mentioned above. The order of execution may vary depending on the specific query and the presence of different clauses.

JavaScript® Notes for Professionals book

📄 400+ pages

🔗 Book Link

#Javascript
➖➖➖➖➖➖➖➖➖➖➖➖➖
Join @web_dev_bds for more

💡 Tips to Crack Top Tech Companies using LeetCode 💻

Are you aiming to crack top tech companies? Here are some tips on how to effectively use the LeetCode platform to enhance your problem-solving skills and increase your chances of success:

1️⃣ Quality > Quantity ✅

Rather than focusing on solving a large number of problems, prioritize the quality of your solutions. It's better to solve a particular Data Structures and Algorithms (DSA) sheet thoroughly and revise it until you can build up the logic on your own. Consider using resources like the Striver Sheet or Grind 75 to guide your practice.

2️⃣ Maintain an Error Sheet ✅

Create an error sheet to keep track of the questions you've solved and the mistakes you've made while solving them. By reviewing this sheet regularly, you can identify common errors and strive to avoid repeating them. This practice will significantly improve your problem-solving skills over time.

3️⃣ Solve Top Interview Questions ✅

When preparing for a specific company's interview, focus on solving recent LeetCode questions that are tagged with that company's name. This way, you'll be familiar with the types of problems the company typically asks and be better prepared for the interview.

4️⃣ For Beginners ✅

If you're new to problem-solving, it's advisable to start with Easy-level problems before moving on to Medium or Hard ones. Aim to solve at least 25 problems in the Easy category before challenging yourself with more complex ones. This approach helps build a strong foundation and boosts your confidence.

5️⃣ Practice Weak Topics Regularly ✅

Identify the topics or problem types that you find challenging or fear the most. For example, if you struggle with graph problems, make it a habit to solve at least one graph problem every day. Regular practice in your weaker areas will help you improve your skills and boost your overall performance.

6️⃣ Don't Ignore Acceptance Level ✅

When browsing problems on LeetCode, consider sorting them by acceptance level. Prioritizing problems with a higher acceptance rate increases the likelihood of successfully solving them. This strategy allows you to build confidence by tackling problems that have been well-received by other users.

7️⃣ Don't Ignore Other Solutions ✅

Even if your solution is correct and accepted, don't overlook the opportunity to learn from others. Explore alternative solutions to the same problem. This practice exposes you to different approaches, algorithms, and optimizations, enabling you to discover new and efficient ways of solving problems.

8️⃣ Consistency is the Key ✅

Maintain a consistent practice schedule to make steady progress. Dedicate a block of time, such as 2-3 hours each day, to solve LeetCode problems. Additionally, set aside a specific day, like Saturdays, for weekly revisions. Consistency and regular practice will sharpen your problem-solving skills and increase your chances of cracking top tech company interviews.

Good luck with your LeetCode journey! 🚀

Prompts for Interview Preparation

1)lawyer:
Imagine you are a law professor preparing a student for an upcoming job interview at a prestigious law firm. I want you to simulate a Q&A session that covers understanding of the law, interpersonal skills, problem-solving abilities, and dedication to ethical practices.

2)Software Developer:
Please provide a set of potential questions, expected responses, and relevant insights for a software developer preparing for an interview in a start-up that specializes in developing educational software tools. Pay special attention to questions on project management, software development methodologies, and specific programming languages.

3)Data Scientist:
Assume you’re a mentor to a data scientist preparing for a role in a healthcare company. Prepare a detailed guide with potential questions, answers, and best practices covering areas like data wrangling, statistical analysis, machine learning models, and domain-specific knowledge related to healthcare.


4)Medical Doctor:
Assume you’re a medical school professor aiding a student preparing for a residency interview. Formulate questions and answers that test knowledge in the chosen specialty, communication skills with patients, and ability to make critical decisions under pressure.

5)Journalist:
You’re a seasoned journalist mentoring a young journalist preparing for an interview at a renowned news agency. Develop a set of questions and possible responses based on journalism ethics, news reporting techniques, and media technology.

6)Teacher:
As a teacher trainer, you’re helping a teacher prepare for an interview at an international school. Develop an interview guide that covers pedagogical approaches, classroom management techniques, and cultural sensitivity.

7)Financial Analyst:
As a financial consultancy firm CEO, prepare a financial analyst for an interview at a Wall Street firm. Provide a set of questions and answers related to financial modeling, equity research, and market trend analysis.

8)Sales Representative:
You’re a sales director preparing a sales representative for an interview at a technology company. Prepare a guide with questions and ideal responses based on sales strategies, customer relationship management, and product knowledge.

9)Fashion Designer:
You’re a renowned fashion designer preparing a budding designer for an interview with a high-end fashion label. Create an extensive guide with potential interview questions and ideal responses, focusing on design principles, understanding of current fashion trends, experience with fabric selection and garment construction, and their approach to sustainable fashion.

10)Marketing Executive:
You’re a career counselor preparing a marketing executive for an interview with a multinational corporation. Develop comprehensive questions and answers that revolve around digital marketing strategies, SEO, content creation, and marketing analytics.