SQL LEARNING SERIES PART-11

Complete SQL Topics for Data Analysis
-> https://t.me/sqlspecialist/523

Let's also learn about Normalization today:

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. There are different normal forms, each with specific rules:

#### First Normal Form (1NF):
- Each column contains atomic (indivisible) values.
- There are no repeating groups or arrays.

#### Second Normal Form (2NF):
- Meets the requirements of 1NF.
- All non-key columns are fully functionally dependent on the primary key.

#### Third Normal Form (3NF):
- Meets the requirements of 2NF.
- Eliminates transitive dependencies, where non-key columns depend on other non-key columns.

#### Example:
Consider a denormalized table:

CREATE TABLE orders (
    order_id INT PRIMARY KEY,
    customer_name VARCHAR(50),
    product_name VARCHAR(50),
    price DECIMAL(10, 2)
);

Normalized to 3NF:

CREATE TABLE orders (
    order_id INT PRIMARY KEY,
    customer_id INT,
    product_id INT,
    order_date DATE,
    quantity INT,
    total_price DECIMAL(10, 2)
);

CREATE TABLE customers (
    customer_id INT PRIMARY KEY,
    customer_name VARCHAR(50)
);

CREATE TABLE products (
    product_id INT PRIMARY KEY,
    product_name VARCHAR(50),
    price DECIMAL(10, 2)
);

Normalization helps avoid data anomalies and ensures efficient database design.

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Hope it helps :)