1. INT – Whole Numbers (No Decimal)

INT is used to store integer values — meaning numbers without any decimal part.
It’s perfect for values like age, quantity, roll numbers, or employee IDs.

Example:

age INT;

2. FLOAT and DOUBLE – Decimal Numbers

When you need fractional or decimal values, use FLOAT or DOUBLE.
They store numbers like 5.75, 99.99, or 3.14159.

• FLOAT: Suitable for approximate values with less precision (e.g., product ratings).
• DOUBLE: Offers more precision and is better for financial or scientific calculations.

Example:

price FLOAT;

3. VARCHAR(n) – Variable-Length Text

Use VARCHAR when you want to store short to medium-length text such as names, emails, cities, etc. You specify a maximum length (n) to limit how many characters can be stored.

Example:

name VARCHAR(100);

4. TEXT – Large Text Content

TEXT is for storing long blocks of text, like descriptions, feedback, articles, or reviews. Unlike VARCHAR, TEXT is meant for when you expect a lot of text.

Example:

description TEXT;

5. DATE – Calendar Dates Only

The DATE type stores values in YYYY-MM-DD format. It’s best for birthdays, registration dates, join dates, etc.

Example:

birthdate DATE;

6. DATETIME – Date + Time Stamp

DATETIME stores both the date and the exact time. It’s great for recording events like logins, signups, updates, or transactions.

Example:

created_at DATETIME;

7. BOOLEAN – True/False or Yes/No

BOOLEAN is used when you want to store binary choices – like whether a user is active, an order is delivered, or an option is selected.

Example:

is_active BOOLEAN;

8. ENUM – Fixed Set of Allowed Values

ENUM lets you limit a column to a predefined list of possible values. Great for things like gender, user roles, status, or categories.

Example:

gender ENUM('Male', 'Female', 'Other');