SQL Window Function | How to write SQL Query using RANK, DENSE RANK, LEAD/LAG | SQL Queries Tutorial

[@Egitam-ow7ih]

Watching his videos I successfully cracked two interviews of Amazon for Data Engineer role , and secured internship.

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damn

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Can you guide me

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what were the questions please ??

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Guys this tutor deserve some award as best tutor in India on Sql and many are cracked toughest interviews after watching his videos.

[@osamaraheem9524]

You explain every things in a clear English, I think this is one of the finest tutorial on KZbin... Keep it Up

[@techTFQ]

Thank you Raheem 🙏🏼 Glad you liked it 🙂

[@KumarHemjeet]

Today i appeared in a SQL test of a company. They had 6 questions. I solved 6/6 and 3 questions were directly based out of windown function. Thanks to this guy. Without him i would have been zero in sql.

[@hellookim]

This was super helpful and easy to follow! I'm currently studying SQL and this was the best explanation of windows functions I came across. Would love to see more videos on SQL!

[@techTFQ]

Thanks a lot for such kind words 🙏🏼 So glad to hear that you found it useful ☺️

[@favourebubechukwu3592]

Agree!

[@techTFQ]

Thank you 🙏🏼

[@meiwarcadey2172]

Thank you so much it is helpful please make more videos on functions in oracle sql

[@techTFQ]

Thank you 🙏🏼 sure will do

[@guitargod2168]

I’ve read countless documentations, articles and watched plenty of other videos but still was facing a hard time grasping the overall concept of window functions. The way he starts with a simple group by query, and then moves on to explain why it has limited use and a window function could be used instead in certain cases, was too helpful for me. Then he breaks down the whole syntax and explains the need for optional arguments depending on the function used, etc. All in all, the concept is explained very well and in a very understandable manner. This has been truly helpful and I am grateful for the video 🙏🏻

[@souryapattanayak9698]

One of best demonstration with absolute clarity about the windowing concept. Thank you for the simplest/easiest explaination of this complex concepts.

[@techTFQ]

Thank you so much 🙏🏼 Means a lot to receive such positive feedback ☺️☺️

[@whatsintrend2761]

Best part is you have a clarity of thought, there's no ambiguity and to the point. And most important queries are not pre written. 👍

[@faridhussain3281]

I am a new SQL learner. So, I saw many videos on SQL tutorials. But, I found your one very helpful and effective. I was struggling with the Window function so hard that I thought I would give up learning SQL. But, your video makes it very simple to me. I am really impressed with your videos. Keep it up.

[@techTFQ]

Thank you so much buddy 🙏🏼 It means a lot to receive such positive feedback ☺️ I am so glad this helped you..

[@apostleisaacopokuagyeman5676]

This gentleman is very practical and a good teacher of SQL. It feels like in person lesson.

[@techTFQ]

Thank you so much Isaac 🙏🏼

[@harshmishra026]

I've search a lot about window function on Google and KZbin but this tutorial is far better than others. It has helped me a lot . What a easy way to explain.✌

[@techTFQ]

Thank you Harsh. glad you liked it :)

[@Moon_Rise6393]

I am power BI developer and i come with 5+ yr of experience buy SQL is something which i didn't used that much except connecting data sources. Since my experience now over 5+ yr so now interviewer want me as Excellent in SQL also and due to not having sql good i got rejected from 10+ interview again and again.... Since I'm about to be jobless i was loosing my hope but when i started watching your video's it's give me a good confidence. I hope now I'll clear interview soon. And god bless you brother to provide these Worthy content ❤ Love you bro ❤🎉

[@animeshmishra4282]

Perfectly Splendid ❄️☕❄️ . I am newly deployed data engineer and I loved how you crafted this concept in simple approach

[@techTFQ]

Thank you , glad this helped

[@omotolamusiliu3539]

This is the best and most comprehensible video I have seen on Windows Function since I have been practising SQL.

[@techTFQ]

Thank you Omotola 🙏🏼 Glad this helped

[@bathini14]

I would have clear the interview today, if I had watched this before ..

[@techTFQ]

Sorry to hear you didn’t clear this time but I hope you get a better opportunity very soon .. Thank you for liking my video🙏🏼

[@samratsingha8515]

@@techTFQsir I want to study your python courses if under my budget Please let me know sir. Thank you

[@sandesh8197]

Same story here

[@ebadulislam123]

I was also asked the same question of finding the top 3 employees from each dept. Sad, I didn't know window functions then.

[@utkarshkunwar4319]

This tutorial, right here, is one of the best to learn what Window Functions are

[@techTFQ]

Thank you Utkarsh for such encouraging feedback 🙏🏼 So glad you liked it..

[@mohammedshahil4898]

Hey brother, Just love the concepts you cover. I could easily understand these window functions. Credits to your teaching skills. You make it so simple and fun. Since i primarily work on SQL, this video was really helpful. Please make more videos on other window functions/advance SQL concepts. Cheers ✌🏻

[@techTFQ]

Thank you Shahil ❤️❤️ Good to know you benefited from this.. Sure will try to cover other functions in another video..

[@zacramer]

I'm preparing for an SQL intensive position and this is a phenomenal overview of windows functions. You provide an overview of the logic then how to apply them to real business questions. Great job!

[@jollypareira688]

Your new subscriber. One of the best channel I came across in learning SQL. You deserve much more subscribers

[@techTFQ]

Woww you made my day by such positive feedback ☺️.. thanks a lot and so happy this video helped you 🙏🏼

[@jollypareira688]

@@techTFQ Thanks to you too for making good contents. Wishinh you all the luck

[@techTFQ]

@@jollypareira688 thank you again 🙏🏼

[@vidyasagarbv89]

I always searched for the syntax of window functions but after your explanation I dont find that necessary because you explained it very well.. 🙏

[@techTFQ]

glad this helped

[@Innovade]

This is the best video I’ve found explaining window functions. Thank you for your help! I really appreciate it

[@techTFQ]

Thanks a lot for the positive feedback 🙏🏼 Much appreciated and so glad the video helped ☺️

[@anubhavasthana8025]

I watch this video as a pre-requisite before every interview... This video has become my reference point... Thanks for being concise and clear :)

[@sheebaparveen3630]

Great. So proud of your intelligence. Your talent of teaching in such simple & understanding way is amazing 👍 Keep growing.

[@techTFQ]

Thank you dearest cheeb ❤️

[@MahaLakshmi-nw3gu]

I was searching to display max (Salary) in all rows for long time..You are my Guru..Thanks alot ..very easy to learn from your video!!!

[@techTFQ]

Thank you Lakshmi 🙏🏼 And thanks for considering my videos with such high regards 🙏🏼 Truly appreciate the gesture 🙂 So glad I could help ..

[@amareshsahoo6003]

This tutorial, right here, is one of the best to learn what Window Functions are. Background slow music is awesome.

[@techTFQ]

Thank you Amaresh 🙏🏼 Glad you liked it..

[@myyouaccounttube1024]

SQL is knowledge, but to know how to teach it in such a beautiful and beginner friendly way, is an art! Bravo for this video. Not only I subscribed to your channel I'll present it to everyone who needs a good course in SQL. 👏👏👏👏👏👏

[@lilprotakeit]

Amazing explanation. I was really pushing back on this part of SQL as i found it very difficult to read from books and blogs but you made it easy man. Thanks a lot !!

[@techTFQ]

So glad to hear that ☺️☺️

[@rasmitahembram4522]

Am I right to say that the problem statement - fetch top 3 employees in each department earning the max salary - can be solved using row_number() as well?

[@vuphan2956]

To be honest, you tech better than some of professors in college. I will watch every of your videos. Thank you.

[@ms_avb]

amazing. i’ve been struggling with window functions and your 25min video has explain it better than a whole day of course material. thanks so much!!!!

[@sachinhipparge393]

seriously i checked many youtube videos to learn sql whenever i start learning by seeing them i feel bore and dificult to learn, thanks to you sir your way of teaching and approach is very different that joins video also seen many times from other youtub pages but never got perfect when i seen your videos on join just in 20mnts whole join concept cleared im realy thanks a lot . even these window functions its just increased my excitement to evolve more on these. great work sir thank you.

[@monishnagarajan5917]

It was an clear explanation with understandable examples, which will be very helpful especially for beginners like me 👏

[@mad24960]

Not a ton of VERY clear advanced SQL Windows functions out there - easy to understand and really clear! Thank-you for the work

[@techTFQ]

Glad you liked it Matthew

[@khushbooagarwal7491]

I was struggling so much with these window functions, thank you truly for this great video lecture. I've never ever commented to any video but this video right here deserves a respect 👏

[@techTFQ]

Thank you so so much Khushboo for this amazing feedback 🙏🏼 I am so glad you took your time to comment on this video.. it feels great to know that this video has helped you understand the concept ☺️☺️

[@khushbooagarwal7491]

@@techTFQ are you planning to make videos on machine learning too?

[@techTFQ]

Yes I plan to do it in the near future.. in the next few weeks will focus on covering some data science concepts and then hopefully will cover machine learning too..

[@coolmedico4887]

You saved my hours of classes to understand such complex concepts in such a short span of time... Thanks bhai...

[@techTFQ]

Welcome:)

[@dhruvmadaan3276]

LOVE YOUR VIDEOS TFQ ! GREAT WAY OF EXPLAINING AND GREAT EXAMPLES ! THANK YOU AGAIN ! WE DONT MIND IF THE VIDEOS ARE LONG, THEY ARE HIGH QUALITY ! WE DONT CARE IF THERE IS BACKGROUND MUSIC OR NOT, THE WAY YOU EXPLAIN MATTERS THE MOST !

[@techTFQ]

Thank you Dhruv once again 🙏🏼 Happy to know you liked them

[@shahrukhtheanalyst]

Best explaination!! I have watched and read 1000s of videos/articles but was unable to grasp window function concepts. This Video really gave a detailed breakdown of how Window Functions work as well as their use cases. Love from Pakistan

[@thedarkknight579]

Best Video on Window Functions that I have watched till now💖💖💖💖

[@techTFQ]

Thank you so much 🙏🏼 Glad this helped ..

[@thedarkknight579]

@@techTFQ I have recently cleared most of SQL rounds because of your video on Window Functions, I request you to continue the good work and plz do some KZbin shorts on advanced level SQL questions, as they could be both interesting to watch as shorts and useful as brain teasers if someone is attending interviews.

[@techTFQ]

Awesome news bro.. am so glad my videos helped you to find a job.®️☺️👌👍 As for shorts, really good idea, let me consider it..

[@kartikjuneja7807]

Bro Honestly this is the best video on analytical functions on youtube. In one go, I understood all the functions completely.

[@techTFQ]

Glad to hear that buddy

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Awesome awesome 👌 You are simply the best, explaining, intention, dedication Perfection. Keep it up. God bless you. Amen🙏

[@techTFQ]

No words to thank you.. still thank you to you for everything 🙏🏼❤️

[@joseinstantpotcook3065]

I owe you a debt of gratitude. Thanks for clarifying so many things for me. At work I inherited a stored procedure that utilized many of the functions you covered. Was lost understanding it and your video turned on all the lights in the house! I am now a subscriber and will go back to the at h your library!!! Take care and stay safe!!

[@techTFQ]

Thank you Jose 🙏🏼 So glad this video helped you ☺️

[@shivkay]

You have the gift of teaching complex stuff in a very friendly and simple manner… best wishes for a great future

[@techTFQ]

Thank you Shiva 🙏🏼

[@fatemehsefishahpar3626]

The most clearest way of explaining window function! Bravo!

[@aperxmim]

Great training, straight to the point, clear examples.

[@techTFQ]

Thank you 🙏🏼 Glad you liked it..

[@aniqahmed7204]

You are an absolute legend for explaining window functions in detail. Thank you so much.

[@animoki9292]

Enjoying every detail.. and as we know every detail matters ..and not many would present with all details.. u r amazing bro..God bless u..

[@techTFQ]

Thank you Ani for taking your time to appreciate my work 🙏🏼 Truly appreciate the feedback 🙂

[@nithiyashanmugam85]

Thanks a lot. I missed some interview because I don't have a knowledge of window function. Now I understand the query because of you. Thanks again. god bless you Bro.

[@techTFQ]

Your welcome Nithiya 🙏🏼 Happy to know this help you understand the concepts

[@singarampalaniappan1736]

Perfectly Explained !! No flaws

[@techTFQ]

Thank you palaniappan 🙏🏼 Glad this helped..

[@ben-9200_]

In 24 minutes you have explained to me window functions in a way better than spending 4 hours in Datacamp

[@jonathanbroyles9247]

This was an extremely helpful review of all the listed window functions. The clear walkthrough of each function and how they interact with each other was done exceptionally well. I was having issues using the lag function correctly and this answered every one of my questions. Looking forward to watching more of your SQL videos! Subscribed! Thank you!

[@techTFQ]

Your welcome Jonathan .. I am glad to read your feedback ☺️

[@emilyshi9417]

This is the most straightforward version of the window function I ever learned. Super helpful! Please teach more advanced SQL language in this channel.

[@christinesong5629]

Awesome! would love to see another video on other window functions. Please do another one!

[@techTFQ]

Thanks a lot 😃 Will be doing another video on other window functions soon..

[@test-hj9lx]

This has become my reference link to revise window functions fundamentals before any sql interview round. Thanks much !

[@nabilraza456]

Such a helpful video to understand windowing functions. That was really helpful.

[@techTFQ]

Thank you 🙏🏼 So glad u liked it 🙂

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These people have literally made youtube platform a university, where you can learn anything for free. ❤

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Couldn't be explained better. Great work.

[@techTFQ]

Thank you so much 🙏🏼 Glad you liked it ☺️

[@yairteshuva2495]

The clearest explanation in KZbin. Great!

[@techTFQ]

Thank you 🙏🏼

[@imsushantjain]

Really good, Thank You!. You should do more SQL tutorials, specially in a structured fashion and starting from basics.

[@techTFQ]

Thank you 🙏🏼 Glad you’ve liked this video. Yeah, I might consider making a complete Sql tutorial playlist from scratch in the near future

[@filiamathioudaki8321]

You have such a detailed and patient way of explaining things, which really makes it easy to understand. Thank you

[@techTFQ]

Thanks you so much 🙏🏼

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Thanks a ton in making these concepts so easy for us to understand . your teaching skills are just outstanding.Please let us know if you have a complete course.

[@rasmitahembram4522]

Am I right to say that the problem statement - fetch top 3 employees in each department earning the max salary - can be solved using row_number() as well?

[@monikabhandari9092]

Thank you so much for making such helpful videos. I have earned gold batch on hackerrank SQL coding just because of you and your content. I love the way you explain the things, It is very simple to understand. Please make a video on solving queries using date and time functions.

[@techTFQ]

Thank you Monika .. I am so glad my videos helped.. And yes will consider your request

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Dear brother...the way you are explaining the things is very easy to understand.. day by day i m increasing my knowledge on SQL...thanks for your all efforts and i wish you all the best!

[@alexharris2375]

Very well done, thank you. I’ve always just ignored Rank because I thought row number does the exact same thing but you’ve helped realize where rank can really be useful.

[@sumanmondal8836]

Please make another video for the remaining parts. Thank You!

[@techTFQ]

Thank you Suman.. will do it..

[@beardy.weirdo]

I have been struggling with understanding window function for a really really really long time. But just one video of yours has made the concepts crystal clear to me. Thanks a lot!

[@satyamsrivastava9034]

I can't tell you how helpful was this

[@techTFQ]

Thank you Satyam 🙏🏼 Glad this helped ..

[@swathikota]

Absolutely brilliant and crisp way of explanation. I had never studied about window functions so far and I just checked your tutorial video to learn, I got crystal clear clarity about window functions - their syntax, usage, scenarios where it can be used. Truly impressed with your teaching skills. Keep teaching, you are doing a great job.

[@atleticoluke]

Thank you so much! That's an amazing explanation!

[@techTFQ]

Your welcome Luiz 🙏🏼 Glad this helped ..

[@muhammadalibhatti538]

This is the best video for explaining the Window functions in SQL, I really do not know about them before watching this video. Well explained by you.

[@iUmerFarooq]

Now everything about sql windows function is cleared. Thank you very much 😉💪🔥 Love from Peshawar, Pakistan 💚

[@TomMosquera01]

I am currently taking up a Data Analysis course via SQL and this was very helpful, since the instructor is having a hard time relaying her knowledge to us learners. Since this was step-by-step and used a basic example, this was more understandable. This topic on the course has a week's worth of lessons, yet I didn't learn as fast as the first 12 minutes of this video. Keep it up!

[@techTFQ]

Super glad this helped and good luck with your learning

[@Jai-id7ik]

Before attend any interview I will definitely check your this video.. Thanks

[@TarabShaikh-q9n]

Only one word for this teaching style - WOW ❤

[@deeprajsarkar3689]

taufeeq the clarity of your teaching is supreme..thank you..

[@shihaosun6861]

This is the greatest SQL video I have ever seen. Thank you sooooo much!

[@techTFQ]

Thank you so much for such an amazing compliment 🙏🏼 So glad to know the video helped ..

[@mehaksaini2552]

This kind of teaching, which relates everything, this is what is needed!! Feeling really grateful for finding this channel where concepts are not just told as they are but their purpose is explained by building upon the examples, step by step.. :)

[@kamogelokhumalo4792]

I didn't know that I would actually end up understanding window functions. This was quite easy to understand. Thanks a lot

[@techTFQ]

Glad this helped

[@timmytesla9655]

I was always scared of learning window functions because I heard people say they are hard. Your video made it very easy for mr. Thank you.

[@paulgideons6960]

this one video explains everything you need to know about window functions in SQL!!

[@eegernades]

sqlzoo's page about this is just returning system errors. So had to search elsewhere to learn and this video shows it in a clear and informative manner. Thanks tremendously for this gem of a video to explain these concepts.

[@snehza1994]

This is one of the best resources for anyone to learn SQL. You have broken down such a complex topic in an easy way that is so helpful for the person getting into advanced SQL whether it is a beginner or someone who has some knowledge, you have made sure everyone understands it well. Thank you so much for this lecture, if possible kindly make a video on rest window functions such as nth value, first value, and ntil. Thanks again :)

[@techTFQ]

Thank you Snehz for the wonderful feedback 🙏🏼 Happy to know this helped.. As for the remaining window functions, I have already made a video about it. Link below kzbin.info/www/bejne/sHLQe4Oaj9priMk

[@snehza1994]

@@techTFQ thank you

[@hasibulhayat9572]

I don't comment in KZbin videos normally. But for this one, I have to! The best video for me when it comes to window functions. Thanks techTFQ!

[@MrRockus]

I was scratching my head on how to selectively extract nth rows from a table, this video was super useful. Thanks.

[@ashutoshsharmaxi]

thank you sooooo much for this video.... I have commented on only 8-10 videos in my whole youtube life and you are one of them... superb explanation...

[@filmzealot3952]

Great video, mate. You saved a lot of time. My head was spinning having listened to the AI teaching voice in my udemy sql course(365 careers). You are awesome

[@rasmitahembram4522]

Am I right to say that the problem statement - fetch top 3 employees in each department earning the max salary - can be solved using row_number() as well?

[@anithan81]

Yes

[@WhizKidd891]

damn, this guy's teaching is clear, precise and straight to the point

[@insightup8743]

I gave a data analyst interview today and just watching this video got me through it. I'm so thankful to you .Tussi great ho sir. Is there any course you have I would love to be a part of it 👍

[@techTFQ]

It's so amazing to read this. I am so glad my video helped you. Congratulations :) As for course, I do live training classes on Lighthall.co I'll announce my next live class very soon.

[@MrPainKillerjxjcidn]

Thank you so much for this, been learning SQL on my own and this is the simplest way to understand window functions.

[@ganeshdhareshwar6053]

This is the best video using which I finally understood the window functions

[@techTFQ]

Thank you Ganesh 🙏🏼 Glad this helped ..

[@Vedanvita]

Hello, Its an excellent channel for SQL. I was asked the same questions in my interview and I watched this video just before it. Love the content. Thank you

[@rakeshgorre4515]

These are some quality content from KZbin rather than Udemy or Coursera.

[@MsShenjie]

Explained the clearest I've see so far. Thank you!

[@techTFQ]

Glad you liked it ☺️

[@asfandpappa]

beautifully explained. You are a hero , I am using this for interview prep and it has taken me from zero to hero

[@igoryanko6386]

Thanks a lot for this video, very straight forward explanations. From my observation in CASE statement we can refer directly to lag() column. Below is an SQL code which works for me (refer to 23:28 timeframe in the video) select e.*, lag(salary) over(partition by dept_name order by emp_id) as prev_emp_salary, case when salary < prev_emp_salary then 'lower' when salary > prev_emp_salary then 'higher' when salary = prev_emp_salary then 'equal' end as sal_range from employee as e;

[@techTFQ]

I believe the above query will throw error. You may have to define "prev_emp_salary" in the subquery and reference it in outer query for it to work.

[@igoryanko6386]

@@techTFQ the query returns expected result in Amazon Redshift (I use SQL Workbench environment) , but it may not work in other SQL dialects

[@techTFQ]

That’s pretty strange… redshift May be designed differently then.. good to know.. thanks for sharing

[@kehagupta142]

you are a great mentor . At first these things were very confusing for me but now i am confident enough to use them. Thank you

[@rohitsurvase4190]

This is a masterclass for SQL window's function, great explanation!

[@balureddy8560]

I appreciate your efforts, the ways of explaining concepts was awesome. But once clarification: I ran this query: -- Fetch the top 3 employees in each department earning the max salary. select * from ( select e.*, rank() over(partition by dept_name order by salary desc) as rnk from employee e) x where x.rnk < 4; Result set: emp_ID emp_NAME DEPT_NAME SALARY rnk 120 Monica Admin 5000 1 101 Mohan Admin 4000 2 108 Maryam Admin 4000 2 116 Satya Finance 6500 1 104 Dorvin Finance 6500 1 118 Tejaswi Finance 5500 3 119 Cory HR 8000 1 107 Preet HR 7000 2 117 Adarsh HR 3500 3 124 Dheeraj IT 11000 1 112 Komal IT 10000 2 122 Ibrahim IT 8000 3 123 Vikram IT 8000 3 111 Melinda IT 8000 3 if you can see the IT dept has given 5 employees but the expected is top 3 employees right? Can anyone clarify this?

[@pging8328]

pedagogical value of vid is sublime. hands down man of the match.

[@SyncWithSrikanth]

Thank you thoufiq, you explained window functions very well. It is one of the best videos about window functions i have seen. Good luck!

[@techTFQ]

Thank you bro :)

[@shujashakir9952]

Thanks Taufiq. The video was enough to teach me the basics of Window functions in SQL.

[@laurak5196]

Your instructions are very clear and you’re really helping me to reinforce what I’m learning in DataCamp. Thanks so much for sharing your expertise with us!

[@techTFQ]

Thank you Laura for this kind feedback 🙏🏼 Glad this video helped..

[@laurak5196]

@@techTFQ All of your videos, I’m finding them very helpful. I’m a new subscriber. Thanks again!!

[@techTFQ]

Thank you again 🙏🏼 And glad to know you subscribed 🙂