Lec 4: Functional dependency in DBMS | What is functional dependency | Database Management System
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- čas přidán 21. 11. 2019
- 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 !!! 🤟
Literally the only video on youtube that explains functional dependency consisely. Thank you.
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.
This is the simplest and most understandable vid I've seen about functional dependency!! Thank u for this great explanation
wonderful explanation.spending 25 minutes by watching this video was really worth. keep it up 👏👏👏
Great lecture. Pls keep posting like this tutorial. your way of teaching and your presentation skills are far better than many professors in USA.
A day before exan , all concepts are clear. Great!
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!!
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
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
Your technique of bringing out the explanation in a simpler and an understandable way is incredible Mam. Keep the good in you 🔥
you are the best teacher. college people just cant explain as good as you do. now this topic is super clear. thanks a lot
Thanku so much mam u have started with dbms, it's my project time ,aap hamesha correct time par aate ho!!😁😁
The only subject I'm learning during online exams is this, because of Jenny it's just great to learn any subject.
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
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.
Its clear now that im functionally depending on these videos to pass my exam, thank you 🙏
Such a great video. and will never forget the concept of FD. Thank You Mam.
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?
The way she teaches just blew my mind!!!! No professor can teach this way🔥🔥🔥
Big thanks from Singapore, this is really detailed and simple to understand
The best explanation on CZcams
honestly your explain is much better than our professor's explain .. massive thank you ...
You are truly an amazing teacher...Thanks a lot.....you made it really simple and easy to learn stuffs for NET / SET preparations.....Love from GOA :-)
Confusions Cleared For Sure After This Lecture!👌
Mem please make the complete video of DBMS, I really want to take this blessings from you ❤🙏
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
Thank you so much!! I was having a hard time understanding it, but you made everything clear!!
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?
@@saranyas8400 nothing is wrong don't worry
@@adityagudla2409 thank you🙂
@@saranyas8400 I think 2nd one is wrong
miss, provide lectures on all topics of DBMS as soon as possible ..... ur lectures are so good .....
What an amazing lecture! Thank you.
Great lecture! Very detailed explanation. Thanks for your help, much appreciated!
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.
Thank you so much mam i got everything is clear.
Thank you for such a blessing
Because of you, I easily grabbed the harder topics of DBMS ❤.
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.
Your are a perfect teacher, thank your from Afghanistan!
Wow you guys study the same thing as us
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
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.
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.
I would have recommended to you to bring the "empty set -> something" example, but all in all a very nice video
Mam u undertand from this in what my teacher couldnt in 3 hours
Thank you so much you really make it clear to me , I was struggling with this functional dependency
wow just wow its amazing video lecture on FD....everything is clear ,,,,thanks jenny ma'am for your grt efforts..
Thank you ma'am for this video 😊😊😊
Thanks Mrs/Miss Jenny, I really appreciate. I'm searching for your lecture on "types of functional dependency"
Yes please types of FD
This is what I call good content!
Very Very Conceptual. Glad to watch this video.
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
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 😁😁😁😍
sister know!!! I appreciate you!!! the very good explanations which you can never miss to understand
Excellent explanation , amazing video. It was very helpful. Thank you so much
One lecture daily ...wow
Good work...working too hard !!!
Do u HV a team???
ThankYou MAM YOurs awll lectures 'S just amazing ..NEEd More in DBMS as soon as possible pLX...
i am following your most of your videos that helps me alot and as a compliment your eyes are so good .....
Mam In this pandemic ur videos really help me... U r so hardworking..thanks a lot
i was waiting for this.
Tomorrow's my exam and you're saving my ass. Thank you so much. 😂
exam hai ya kuch aur
Thank You very much! Amazing Explanation Skills!
love it, Jenny! So clear and concise!
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...🙆🏻😂
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... ❣️
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❤️
This is the best explanation on the internet in my opinion
You haven't told about full, partial,transitive dependency
Please do relational algebra next!
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 ,
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
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.
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
Very well explained! Thank you for what you are doing for us.
Thank you for going through the topic in depth. Excellent explanation
Deepa Maam oligaaa !!😶🌫 apoo puriyala !! ipoo puriyuthuu ! ! !☺
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
Fantastic explanation mam...now I got the functional dependency
That was great lesson. Thanks for your spending time on this
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
Roll number -->correct
Dept, course -->incorrect
Roll number,marks -->correct
name -> course --->incorrect
name ,marks,dept -->incorrect
same
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
Most important things for s/w development
#Algorithms
#Functional Programming
#Data Structures
So tysm for making these videos 👍
Don't even know what DBMS is but still watching😳
😭☠️
when u will cover ERD + cardinality + relationship
Yesss
@@Vivek_Mohapatra i
Lovely indeed. I understand this functions the way it was meant to be.
wow, this is the best explanation I ever heard. good work. I am highly appreciate the effort.keep going ma'am.
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 😂
😅😅😅
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 must say best video on youtube explaining functional dependency,better than gate smashers
Thank you mam.... Very easily I've got FD concept,, just bcz of your hard work.
1)fd
2)nfd
3)fd
4)nfd
5)nfd
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.
Thank you very much.
Earlier I didn't know what functional dependency is, now I clearly know what functional dependency is.🥰😘
Just the beginning was enough for me amazing video.
So the topic is Infix to pastfix using stack 😛😜😜
Thank you, ma'am, for a wonderful and clear explanation. Fortunately, I came across your channel, otherwise I would have got lost in the slides of the lesson.
Really love the way you explain...thank you madam may God give you all needs
Beautiful!!!!!Both you and your class!