The best Tutor I ever met who made me understand Normalisation within a period of 10 minutes wow. Good job🥰🥰🥰 I am repeating this module as supplementary but I'm telling you with your tutorial lessons il make it 🤗
That's not true. You only need to know the studentid to know the name. So in practice, I would create a new table called Student with student id as primary key and student name as non-key column
But in d example for 3rd NF , max marks is dependent on exam type ...not student id ...means maxmarks is not fully functional dependent on primary key(which is student id) ...so it seems like d case of 2nd normal form only
in 2NF you have set Primary key to two fields(columns) which is not possible in ms access because a primary can only have unique values and not repeating values, and it cannot have null(empty) values as well. in MS access both two columns cannot have primary key, and a value that repeats (in a column).
great explanation. I have a doubt though. At 5:26 can't we separate the name column together with student id in a separate table. Isn't student name dependent on just student id but not the course?
Thank u , but then again student id is the part of primary key , so we cant disturb that part on the other hand teacher and course are not part of primary ,thats why we can move them , if you ve liked the video please d me a favor and share it wherever you can
Doesn't the new table created at 2:50 also violate 1NF though? Because of the repeating names? I personally thought it should be a table consisting of employeeID linked with phone numbers, but I'm not sure, could be wrong
composite key is when there is a need of more than one column s combination to be unique,here id and course is repeatable but not the combination of both , so this combination is the composite key here
@@SaghirSchool Dude even in the new table which u have formed for 2NF is not deprived partial dependency See partial dependency means if part of your candidate key within a composite key is functionally dependent on any NON-prime attribute its not in 2nf. Here SID+Course is the composite key , SID functionally dependent on Name and Also Course is functionallly dependent on Teacher ,So there is two partial dependencies but you have solved to remove one partail dependency only i will descibe below how it should may be helpful for some people - studentid which has partial dependency on name hence its not still in 2nF, You should have divided it into 3 tables to make it deprived of 2nf like Table1-SID,NAME Table2-Course,Teacher Table3-SID,Course,Marks now only its in 2NF
Am a bit confused in the student ID primary key(201)..I thought primary key columns can't have repeating rows...and 201 appeared twice am not a pro so if this question sounds silly, please bear with me😊
you must be talking about the 2nf part , its a different thing all together where there is a need of more than one primary key combinations to make it primary , in that one column can repeat itself but but the combination of columns which is unique and giving it the difference factor, there is a same video made on this in hindi as well if u want it so
@@suprajaiyer2000 there can be a situation where we need more than one primary key column if we know that there is a possibility of repetition of a value in a column then combination of two columns are taken as primary , if we r certain that the combination of two columns is totally unique then problem solved and keep in mind there can be more than two primary columns as well
In the 2nf that you have described.......why only teacher is partially dependent while student_name also only depend on Id i.e student_name nothing to do with course name...Id is enough to identify student....can we remove that column ??????
What I think is, if someone is a student then he must have any course, otherwise his name doesn't have any purpose to get enlisted in this table, and hence s.name depends on course name too.
@@SaghirSchool I think they mean that in the 2NF example. the non-key column "Name" is dependent on only the Primary Key "StudentId". Since "Name" isn't dependent on the Key column "course", shouldn't name also be removed and made into a seperate table?
