Core Concept Mastery • DBMS Module
Imagine a strict classroom seating chart.
The Rule: Only ONE student per chair.
The Violation: Two students trying to squeeze into a single chair because they are best friends ("Math, Science").
The Fix: You must bring an extra chair. Now, "Student A sits in Chair 1" and "Student A sits in Chair 2". Yes, the student appears twice in the room list, but every chair has exactly one person. This is 1NF.
If you store "Math, Science" in one cell, the computer can't count them, sort them, or filter them easily. It's like glueing two pages of a book together.
Bad: [Name: Jon, Subjects: "Math, Science"]. Good: Split it into two rows -> [Jon, Math] and [Jon, Science].
"If an attribute contains multiple values (comma separated), which normal form is violated?"
1NF.