Multiple columns in a table can contribute to the overall Primary Key. For example, in the Classroom table he has 'building' and 'room_no' working together to form the primary key. So you can have the same building # listed, as long as each of the room #'s are unique within that building. Similarly, the same room # can be used, but only if that room # appears in unique building #'s. So, when the two columns are combined, the following entries are each unique within the table: Building 1, Room 1 Building 1, Room 2 Building 2, Room 1 Building 2, Room 2 Since the 2 columns work together as the Primary Key, you could NOT have: Building 1, Room 1 Building 1, Room 1 (
I recognised this sir by his voice, saved me an year ago in CN , now same with DBMS , thank you sir, grateful to have people like you on UA-cam
Do not stop , plz.DataBase has become exciting
Can you make a video tutorial converting ER diagram to Schema Diagram?
Thank you very much for such a detailed explanation!
Crystal clear sir
I have no words thnks so much dear
You guys are really epic>>>
Explanation is clean 👍
In previous video u said we cannot define more than one primary key in single table sir? But here we are defining
Multiple columns in a table can contribute to the overall Primary Key. For example, in the Classroom table he has 'building' and 'room_no' working together to form the primary key. So you can have the same building # listed, as long as each of the room #'s are unique within that building. Similarly, the same room # can be used, but only if that room # appears in unique building #'s.
So, when the two columns are combined, the following entries are each unique within the table:
Building 1, Room 1
Building 1, Room 2
Building 2, Room 1
Building 2, Room 2
Since the 2 columns work together as the Primary Key, you could NOT have:
Building 1, Room 1
Building 1, Room 1 (
Thank❤you
which type of schema diagram is it, relational schema or database schema
Please upload videos on this course
Thank u for every vd u posted
sir your lecture is like Video Format of Database System Concepts by.(Abraham silberschataz,henry and S.sudarshan)
Hi , how to i get your full course of data structure and discreet mathematics and others gate and UGC net concept please give me permission
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