Uploaded January 2022 | Updated September 2026, 28 minutes ago
In this video, We will show you how to join multiple tables in SQL and the importance of LEFT JOIN vs INNER JOIN. We’ll also talk about things to watch out for when joining multiple tables.
To show you how this works, we’ll use the LinkedIn interview question we’ve categorized as medium difficulty. Here's the link to the question: platform.stratascratch.com/coding/2055-average-customers-per-city?python=&utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
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👉 Subscribe to my channel: bit.ly/2GsFxmA
👉 Playlist for more data science interview questions and answers: bit.ly/3jifw81
👉 Playlist for data science interview tips: bit.ly/2G5hNoJ
👉 Practice more real data science interview questions: platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
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Timeline:
Intro: (0:00)
Reference Table Concept: (0:20)
Interview Question: (0:38)
The Code: Inner Joining Multiple Tables: (1:04)
The Output: Inner Joining Multiple Tables: (2:31)
LEFT JOIN vs INNER JOIN: (3:33)
The Reference Table With The LEFT JOIN: (5:18)
The Code: LEFT Joining Multiple Tables: (6:16)
The Output: LEFT Joining Multiple Tables: (6:43)
Conclusion: (7:13)
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About The Platform:
I'm using StrataScratch (platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link), a platform that allows you to practice real data science interview questions. There are over 1000+ interview questions that cover coding (SQL and python), statistics, probability, product sense, and business cases.
So, if you want more interview practice with real data science interview questions, visit platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link. All questions are free and you can even execute SQL and python code in the IDE, but if you want to check out the solutions from me or from other users, you can use ss15 for a 15% discount on the premium plans.
______________________________________________________________________
Contact:
If you have any questions, comments, or feedback, please leave them here!
Feel free to also email me at nathan@stratascratch.com
______________________________________________________________________
#JoinMultipleTablesInSQL
In this video, We will show you how to join multiple tables in SQL and the importance of LEFT JOIN vs INNER JOIN. We’ll also talk about things to watch out for when joining multiple tables.
To show you how this works, we’ll use the LinkedIn interview question we’ve categorized as medium difficulty. Here's the link to the question: platform.stratascratch.com/coding/2055-average-customers-per-city?python=&utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
______________________________________________________________________
👉 Subscribe to my channel: bit.ly/2GsFxmA
👉 Playlist for more data science interview questions and answers: bit.ly/3jifw81
👉 Playlist for data science interview tips: bit.ly/2G5hNoJ
👉 Practice more real data science interview questions: platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
______________________________________________________________________
Timeline:
Intro: (0:00)
Reference Table Concept: (0:20)
Interview Question: (0:38)
The Code: Inner Joining Multiple Tables: (1:04)
The Output: Inner Joining Multiple Tables: (2:31)
LEFT JOIN vs INNER JOIN: (3:33)
The Reference Table With The LEFT JOIN: (5:18)
The Code: LEFT Joining Multiple Tables: (6:16)
The Output: LEFT Joining Multiple Tables: (6:43)
Conclusion: (7:13)
______________________________________________________________________
About The Platform:
I'm using StrataScratch (platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link), a platform that allows you to practice real data science interview questions. There are over 1000+ interview questions that cover coding (SQL and python), statistics, probability, product sense, and business cases.
So, if you want more interview practice with real data science interview questions, visit platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link. All questions are free and you can even execute SQL and python code in the IDE, but if you want to check out the solutions from me or from other users, you can use ss15 for a 15% discount on the premium plans.
______________________________________________________________________
Contact:
If you have any questions, comments, or feedback, please leave them here!
Feel free to also email me at nathan@stratascratch.com
______________________________________________________________________
#JoinMultipleTablesInSQL
![Data Science SQL Interview Question Walkthrough [Microsoft] - Window Function: Ranking](https://i.ytimg.com/vi/i-E4pdU2qXM/mqdefault.jpg "Data Science SQL Interview Question Walkthrough [Microsoft] - Window Function: Ranking
This Data Science SQL interview question is from Microsoft, and tests your ability to write window functions to rank data. I’ll walk you through solving the question like we’re in an interview and give you some tips on how to approach the solution.
Go to the question through the link below and follow along with me.
Link to the question: https://platform.stratascratch.com/coding/2026-bottom-2-companies-by-mobile-usage?python=&utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
👉 Subscribe to my channel: https://bit.ly/2GsFxmA
👉 Playlist for more data science interview questions and answers: https://bit.ly/3jifw81
👉 Playlist for data science interview tips: https://bit.ly/2G5hNoJ
👉 Practice more real data science interview questions: https://platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
Timeline:
Intro: (0:00)
Interview Question: (0:31)
Framework to solve the problem: (1:25)
Understand your data: (2:33)
Formulate your approach: (5:05)
Code Execution: (7:09)
Code Optimization: (15:54)
Conclusion: (18:10)
About The Platform:
Im using StrataScratch (https://platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link), a platform that allows you to practice real data science interview questions. There are over 1000+ interview questions that cover coding (SQL and python), statistics, probability, product sense, and business cases.
So, if you want more interview practice with real data science interview questions, visit https://platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link. All questions are free and you can even execute SQL and python code in the IDE, but if you want to check out the solutions from me or from other users, you can use ss15 for a 15% discount on the premium plans.
Contact:
If you have any questions, comments, or feedback, please leave them here!
Feel free to also email me at nathan@stratascratch.com
#MicrosoftDataScienceInterview")
![Top Data Science Interview Question And Answer Mistakes 2021 [Asked By Amazon]](https://i.ytimg.com/vi/j8kGqAAIhxA/mqdefault.jpg "Top Data Science Interview Question And Answer Mistakes 2021 [Asked By Amazon]
Were going to cover the #1 most common mistake made on data science interviews. This mistake is made by both inexperienced and experience data science professionals; it happens both on interviews and in the work setting; and the mistake takes place when trying to solve the most common data science question. Lets cover it so that you dont make the same mistake.
Follow me interactively with the question here: https://platform.stratascratch.com/coding/9915-highest-cost-orders?python=&utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
Platforms I recommend to practice data science real scenarios:
- https://platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link (data science questions)
- https://leetcode.com (general database questions)
- https://datacamp.com (niche specific analytical skillsets)
👉 Subscribe to my channel: https://bit.ly/2GsFxmA
👉 Playlist for more data science interview questions and answers: https://bit.ly/3jifw81
👉 Playlist for data science interview tips: https://bit.ly/2G5hNoJ
👉 Practice more real data science interview questions: https://platform.stratascratch.com/coding?utm_source=youtube&utm_medium=click&utm_campaign=YT+description+link
Timestamps:
Intro: (0:00)
Description of the most common mistake: (0:34)
Coding example of mistake: (1:00)
How to properly solve the question: (4:50)
Reason why youre making these mistakes: (7:30)
Recommendations to improve: (8:10)
Contact:
If you have any questions, comments, or feedback, please leave them here!
Feel free to also email me at nathan@stratascratch.com
#datascience #sqlinterviews #codinginterviews")
