Lec 4: Functional dependency in DBMS | What is functional dependency | Database Management System
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- Опубликовано: 23 ноя 2024
- Jennys lectures DSA with Java Course Enrollment link: www.jennyslect...
In this lecture I have explained functional dependency in DBMS with proper example. Here you will find simplest explanation of functional dependency in DBMS.
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I've had 2 three hour lectures so far on this topic and didnt understand anything there. And after 25 mins here I basically grasped everything. Thank you very much for this video!
same with me,,,thanks for great leacture
you are just dumb
Wow , could not understand anything in college but here just 20 mins and the concept is very clear great effort :) Thanks ma'am
simp
@@I3uzzzzzz word bro
@@I3uzzzzzz 🤣🤣🤣🤣
me too same bro. Effect of online class.
me too same bro. Effect of online class.
Excellent ! I have never seen a video so far which explains "Functional Dependency" in such a simple way. I wish I had this facility 30 years ago.
Hello.
Just started watching DBMS and since im from greece im very glad you are doing all this great work in english . I wish you the best .
Nice
I'm from Mechanical Branch, but the way you explain DBMS is outstanding. I mean, it's really easy for me to get those things in my head, when you explain.
Thank you so much Ma'm !!!
I really appreciate your way of teaching !!! 🤟
I very much appreciate these lectures. I am currently going through graduate school, and this is far easier to understand than my database book while also covering the exact same concepts. Thank you.
Brilliant.
I recently joined my job after campus placement as dwh engineer. I am from ece and not cs, your videos are extremely helpful before i get on learning about data warehousing.
Thanks a lot for spreading knowledge in clear and concise manner!!
Its clear now that im functionally depending on these videos to pass my exam, thank you 🙏
Literally the only video on youtube that explains functional dependency consisely. Thank you.
even my sir have confused when students of my class asking doubt while teaching functional dependency in my college.
but u have cleared this topic.
Thank you! I'm only half way through the video but it's already making way more sense then how my online course was teaching it. They were teaching X -> Y should be read as Y is dependent on X, which is true but for someone learning the concept reading it as X determines Y makes it much more clear.
Excellent Ma'am looks like I am taught by someone who is a Professor from a prestigious university who has huge knowledge on the subject and has a unique skill to make her student understand the topic at one go. Thank you Ma'am to make us understand every topic at one go.
Hello Mam,I'm a CS student From Bangladesh.Your Explanation is really amazing.Properly understand this topics only in 20-22 mins.God Bless Mam.Stay Home,Stay Safe.Love from Bangladesh
Thank you ma'am for this series. Since there are so many subjects for GATE preparation, I don't have time to go through them all. Seeing all your videos was actually enough to solve most of the major GATE questions from DBMS, especially from functional dependencies. Your theoretical knowledge in this subject is very good, and your explanations are clear and simplified. May you continue to be a Teacher who serves us students so well!
Great lecture. Pls keep posting like this tutorial. your way of teaching and your presentation skills are far better than many professors in USA.
It is rightly said that even if you hesitate or have trouble expressing something but deep down you understand the root of anything you can just make anyone understand you just have to use and be simple about it !!
Thanks mam ❤
This is the simplest and most understandable vid I've seen about functional dependency!! Thank u for this great explanation
The way she teaches just blew my mind!!!! No professor can teach this way🔥🔥🔥
The only subject I'm learning during online exams is this, because of Jenny it's just great to learn any subject.
How can college professors can mess up students with this simple concept, why I don't know! hats off to Jenny, you made things so easy. Lot's of love from Japan
Your technique of bringing out the explanation in a simpler and an understandable way is incredible Mam. Keep the good in you 🔥
Not sure why my PhD professor did not explain this concept this way. This is so easy but he decided to use fancy words and mathematical terms to explain the concept and made it so confusing. I think being a teacher is finding ways to describe any concept in the simplest terms possible that anyone can understand. Thank you Jenny.
1. OK, all x different.
2. OK, all x (combination of Dept, Course) are different.
3. OK, all x (combination of R. No, Marks) are different.
4. No, Name a can correspond to 2 different courses (C1, C2) and name b can correspond to C1 or C3.
5. No, combination of (a, 78, CS) which is x can correspond to R. No. = 1 or 3, and (b, 60, EE) can correspond to R.No. = 2 or 4.
Be sure to understand that at the left of the arrow represents x. Do not decompose the combination when analyzing a F. D.
but i think second one is no fd
@@divyarana9717 I agree with you, the courses are not the same
@@divyarana9717 it is FD bro
My answer is also same
Yes
Yes
Yes
No
No
@@divyarana9717 (CS, C1) & (CS, C2) are 2 different values of 'x', so it is FD
A day before exan , all concepts are clear. Great!
Thanku so much mam u have started with dbms, it's my project time ,aap hamesha correct time par aate ho!!😁😁
Ma'am u teach all the cases so that u do nat have any problem to solving questions thanku so much for your help
1 Roll no --> Yes
2 Dept, Course --> Yes
3 Roll no, Marks -->Yes
4 Name --> No
5 Name,marks,dept -->No
@Danyal Zia ...kyu bro
@@abhishekmaurya9503 dept is same but course is different
@@abhishekmaurya9503 sorry it has dependency
The same answers too)) So I got the topic) Let's move to the next video))
@@JawwadHussain08 can u explain why? since dept cs once has c1 and once c2, and ee once has c1 and once c3, we should not check further, i thought?
Big thanks from Singapore, this is really detailed and simple to understand
wonderful explanation.spending 25 minutes by watching this video was really worth. keep it up 👏👏👏
i understand some points about functional dependency from first 8 mins but after explain with example i understand this concept thank you so much mam
answers 1.FD (functional dependency)2.FD 3.FD 4.NFD 5.NFD(Not functional dependency )
miss, provide lectures on all topics of DBMS as soon as possible ..... ur lectures are so good .....
Mem please make the complete video of DBMS, I really want to take this blessings from you ❤🙏
For the exercise in 25:34
The answers are :
1) Is a Functional Dependency (FD)
2) FD
3) FD
4) Not a Functional dependency (NFD)
5) NFD
Remember 1 thing :
For 2 tuples t1 & t2 in R
If t1.x = t2.x
Then t1.y = t2.y
For an FD,
▪︎ If first condition for FD holds , then second condition must & should be true..
▪︎ If first condition itself is false (as is the case for exercise probs 2 & 3 above), then by default it's a Functional dependency.(Check example in 14:52 for this)
@vs
Condition :
If t1.x = t2.x
Then t1.y = t2.y
For 2nd & 3rd probs, the first condition i.e, t1.x = t2.x (if part ) itself is not true...
[ if x is a set of attributes, then all attributes must be repeated in both tuples t1 & t2.. for this 👆 condition to be true.. ]
That is not the case, so, there is no need to check the else part.. by default, it's a Functional dependency...
Check the example in 14:52 for this case..
Bro 2nd is NFD
How is 1st a functional dependency no roll no. Is same
@@vanshika5721
Default FD..
Check example solved at 14:52
@Akash Pawar
For second question, the FD given is of the form X --> Y.
Where X is a set of attributes, X = { Dept, Course } . Here Dept values are repeated, but the Course values are different for the repeated Dept values.... so these 2 pairs of X's (sets) :
t1.X = (CS , C1) , t2.X = (CS , C2) in first case , where both aren't equal ..
In second case,
t1.X = (EE, C1) , t2.X = (EE, C3) again, both are not equal..
.. so, it's an FD by default ...
[ because 1st condition ; t1.X = t2.X itself is not satisfied in any case .. , so no need to check else part., it's an FD by default .. check example at 14:52 ]
2nd one is NFD
my conclusion is that functional dependency means the attributes are having 'function-like' corresponding relationship.
very detailed introduction! thks a lot!
1. RNo ->Name, marks✔️
2. Dept, course -> name ✔️
3. Rno market -> Dept ✔️
4. Name -> course ❌
5. Name,marks,dept ->Rno ❌
Thank you mam ❤
Check again
@@nadeemyousuf4332 y.
Which one wrong?
@@saranya8157 nothing is wrong don't worry
@@adityagudla2409 thank you🙂
@@saranya8157 I think 2nd one is wrong
1. true
2. true
3.true
4.false
4.false
Thank you so much !! i understood this concept very well !!
Thanks Mrs/Miss Jenny, I really appreciate. I'm searching for your lecture on "types of functional dependency"
Yes please types of FD
OMG.:))Thank you so much madam. I have watched your DBMS lecture videos and they're absolutely amazing.
You can explain any situations with excellent solutions although my college teachers can't.
The best explanation on RUclips
Thanks MAM. In reality , reading it lot of times, but you cleared the concept by single formulae. if t1.x=t2.x then t1.y=t2.y . superb
Your are a perfect teacher, thank your from Afghanistan!
Wow you guys study the same thing as us
Indian RUclips Teachers are revolutionazing education
Mam u undertand from this in what my teacher couldnt in 3 hours
Thanks Jenny coz this FD concept can confuse especially when the use of the word "determine" is not explicitly explained. Just realized it's what was holding me back.
Marks -> dept [ No ]
As for marks 80 we have different values IT and EC [ × ]
Look above for marks 78.
It's confusing because for 78 and 60 this condition true but for 80 it's false
This is true, I think if one condition is false then this is not functional dependency.
Its functional dependency because a test case of relation is true 78 78 and cse cse.
@@mdomarfaruq3160 better use this generalization
Mam your tech us in so simple and lucid language. thanks a lotttttt....
Such a great video. and will never forget the concept of FD. Thank You Mam.
Because of you, I easily grabbed the harder topics of DBMS ❤.
Confusions Cleared For Sure After This Lecture!👌
Thank you very much.
Earlier I didn't know what functional dependency is, now I clearly know what functional dependency is.🥰😘
You are superb. Thank you so much for the video. Content and quality are just fabulous. Keep going and keep on teaching us. Love from Kerala.
you are the best teacher. college people just cant explain as good as you do. now this topic is super clear. thanks a lot
I would have recommended to you to bring the "empty set -> something" example, but all in all a very nice video
Maam thanks you saved me... i found your lecture at the amity university web suggested videos.... the professor taught the same thing couldn't understand a thing... I felt like I am stupid.. later when i saw your lectures. i am at peace now.. i understand every thing. great job Maam... (and you are very cute[a compliment with full respect as a Maam., not otherwise])
Thank you so much mam i got everything is clear.
Thank you for such a blessing
I really appreciate the way you explain mam. I am working in different domain and want to switch my career in IT . Your explanation is easy to understand even for non IT professionals.
Its like I am attending two colleges at the same time, my current one in the morning where I don't understand anything and here in Jenny Ma`am classes in the evening to understand what I didn't in the morning.😁😁😁
Hahahahahahahaha......OMG ......this is good
honestly your explain is much better than our professor's explain .. massive thank you ...
Thank you mam ..now. I am in semester holiday ...it will be very useful to spend my time with your videos 😍😍😍😍dbms and then operating system we want 😁😁😁😍
Thanks ma'am for helping us , we are surviving in fake teachers world because no one gives correct and easy knowledge so much irritating.
But thankfully your explanation is just wow I am able to understand the concept easily.
Thanks ma'am.
Tomorrow's my exam and you're saving my ass. Thank you so much. 😂
exam hai ya kuch aur
She's the teacher what students want to really learn something ❤❤
Thank you ma'am for this video 😊😊😊
Answers =>
1. Yes
2. Yes
3. Yes
4. No
5. No
hello can u explain the second case..
( dept , course ) --------> name
Here dept, course is not repeated .. cs,c1 != EE,c1 != CS,C2 != ..... So here if any one is same then it checks the corresponding name is same or not . If same then functionality dependency otherwise not.
Can you explain the 4th case. I think it should be FD.
This is the best explanation on the internet in my opinion
Your explanations are crystal clear mam! Also my name is Nisha too :)
functional dependency
who's dharmini then?
@@kaustubhpaturi4801 my nickname is nisha
@@talentaptitude3017 I'll take that...🙆🏻😂
You are just so good at teaching , I had ask gpt about this concept but still don’t get it, however , you just helped me grasp this concept so quickly, thanks a lot
Roll no-->Name,marks (yes FD)
Dept,course-->Name(yes FD)
Roll No ,Marks-->dept(yes FD)
Name-->course(no FD)
Name marks,Dept-->Roll no(no FD)
Why 5 isn't FD
@@HendersonHarrisson because rollno is different
Actually you are great. Your teaching style is very easy I'm also learning from your every lecture.
Some days ago i was confused different types of key but now I'm very clear. Thanks Thanks a lot.
From Bangladesh
ThankYou MAM YOurs awll lectures 'S just amazing ..NEEd More in DBMS as soon as possible pLX...
Mammmmmm...❤❤
thankyou so much mam...
i am trying to understand this topic and i am tired...
i lost interest in rdbms...
then your lecture came as saviour❤️🌟🌟🌟🌟🌟
thankyou once again,lots of love mam... from Hyderabad,india
One lecture daily ...wow
Good work...working too hard !!!
Do u HV a team???
Thanks Ms. Jenny i'm from Saudi and yet you literally save me THANKS A LOT
Don't even know what DBMS is but still watching😳
😭☠️
Thank you mem for wonderfull lecture. The one i was struggling to understand and scratching my head you explained in simple words. that's amazing and i am so thankful for this and pray for your well wishes. This captivates my heart❤❤.
Hi Mam, It would be really great if you could suggest the sequence to learn data structures and also algorithms and which one to pickup first among them ?Thanks in advance
Mam In this pandemic ur videos really help me... U r so hardworking..thanks a lot
Deepa Maam oligaaa !!😶🌫 apoo puriyala !! ipoo puriyuthuu ! ! !☺
Thank you mam.... Very easily I've got FD concept,, just bcz of your hard work.
R u roll that roll number 15 th student... because u had mentioned the same number in another videos too🤣🤣
Anyway again a awesome lecture from my favorite teacher... ❣️
sister know!!! I appreciate you!!! the very good explanations which you can never miss to understand
You haven't told about full, partial,transitive dependency
thank you so so much for this excellent explanation ma'am, for weeks I can't understand this but you made is possible in 20+ mins ,
Please do relational algebra next!
to be honest your 10 thousand times bettr thn our collage your explanation is clearcut and great learnt this in 30mins massive thanks to you mam /\
I came here for functional dependencies, now I'm functionally in love.
This love function is surely many-one and not one-one xD
Lol tha functional love is gonna drown you for sure 😂😂
@@poopanda1999it's one to many, I think 😂
😅😅😅
SUPER MADAM I UNDERSTOOD EVERYTHING IN YOUR EXPLANATION
Roll number -->correct
Dept, course -->incorrect
Roll number,marks -->correct
name -> course --->incorrect
name ,marks,dept -->incorrect
same
Worth of it, thank you very much for such a wonderful explanation.
Below are Answers for questions.
1. F.D
2. No F.D
3. F.D
4. No F.D
5. No F.D
2 is F.D... check clearly. Becoz there are no duplicates in X(dept, course) so it obviously FD.
@@viratriyaz2634 the dept cs and ee are same but their corresponding courses are different ie. Cs-> c1 , ee-> c1 and cs-> c2 , ee -> c3 so here x values are not same so no need to check for y .
2 is also FD
1)fd
2)nfd
3)fd
4)nfd
5)nfd
Well thanks for this video after seeing your video now I can easily understand what my teacher teaches me so thank you very much again❤️
Wouldn't the definition be something like this :
if( t1.x == t2.x ) AND if( t1.y == t2.y )
then "It is functional dependency"
AND IF ( t1.x != t2.x) then "It is functional dependency"
ELSE "It is not!"
Right
Exactly
This is what I call good content!
when u will cover ERD + cardinality + relationship
Yesss
@@Vivek_Mohapatra i
Marks->Dept is functional dependency because the condition {t1.x=t2.x, t1.=t2.y} is satisfied.
No its not a FD
R.no-->marks-func.dependency.
dept,course-->name-func.dependency
r.no-->marks-func.dependency.
name-->course-not a func.dependency.
name,marks,dept-->r.no-not a func dependency.
i haven't a word to express ur capacity and willingness jenny ! ur the best of bests by ur teaching , beauty and and many others ... at he end i....u
1.R.no-> name,cource --- fd yes
2.dept,course->name---no
3.r.no,marks->dept---yes
4.name->course--no
name.marks,dept->r.no--no please conform is it right
No. 2 is FD
i am following your most of your videos that helps me alot and as a compliment your eyes are so good .....
i was waiting for this.