Normalization is the process to eliminate data redundancy and enhance data integrity in the table. Normalization also helps to organize the data in the database. It is a multi-step process that sets the data into tabular form and removes the duplicated data from the relational tables.

#First Normal Form (1NF): Ensuring Atomicity and Uniqueness

A table is in 1NF if:

Each column contains atomic (indivisible) values – meaning each field must contain only one value, not multiple values or lists.
Each row must be unique – so there are no duplicate rows. eg

student_id	name	courses
1	John Doe	Math, Science
2	Jane Doe	History, Literature
this table is not in 1NF because the `courses` column holds multiple values (Math, Science). To bring this table into 1NF, we need to split the multiple values into separate rows.

student_id	name	course
1	John Doe	Math
1	John Doe	Science
2	Jane Doe	History
2	Jane Doe	Literature
now each field has atomic values and each row is unique – so the table is in 1NF.

#Second Normal Form (2NF): Removing Partial Dependencies

A table is in 2NF if:

It is already in 1NF.
Every non-key column is fully dependent on the entire [[Primary Keys |primary key]], meaning there are no partial dependencies.
Partial dependency occurs when a non-key column depends only on part of a composite primary key (when the primary key consists of more than one column). Suppose you have a student_courses table like this:

student_id	course_id	student_name	course_name
1	101	John Doe	Math
1	102	John Doe	Science
Here, the `student_name` and `course_name` columns depend only on part of the composite key (either `student_id` or `course_id`), but not both. This violates 2NF.

#Students Table:

student_id	student_name
1	John Doe
2	Jane Doe

#Courses Table:

course_id	course_name
101	Math
102	Science

#StudentCourses Table (Associating students with their courses):

student_id	course_id
1	101
1	102
now, every non-key column is fully dependent on the entire primary key, and the table is in 2NF.

#Third Normal Form (3NF): Removing Transitive Dependencies

A table is in 3NF if:

It is already in 2NF.
There are no transitive dependencies, meaning no non-key column depends on another non-key column.

student_id	student_name	department	department_location
1	John Doe	Math	Building A
2	Jane Doe	History	Building B
in this table, `department_location` depends on `department`, not directly on `student_id`. This is a transitive dependency and violates 3NF.

To remove the transitive dependency, split the table:

#Students Table:

student_id	student_name	department
1	John Doe	Math
2	Jane Doe	History

#Departments Table:

department	department_location
Math	Building A
History	Building B