SQL Data Types Explained with Examples

SQL Tutorials

SQL data types tell the database what kind of data a column can store. They control how values are saved and processed. As a result, choosing the right data type keeps your database fast and reliable.

What Are SQL Data Types

SQL data types specify the type of value that a column must hold.
In a table each column has one data type.

However, names are a text data type. For example,
In addition, ages and prices are both defined to be numeric types.

Numeric Data Types

Numeric data types only store numbers.
With this in mind, they are preferable for counts, prices and totals.

Data Type	Example	Use
INT	25	Whole numbers
BIGINT	9876543210	Large numbers
DECIMAL(5,2)	99.50	Exact decimals
FLOAT	12.75	Approximate decimals

Example

CREATE TABLE products (
  id INT,
  price DECIMAL(6,2),
  stock INT
);

String Data Types

String data types hold text values.
You will generally use them for names, emails, titles.

Data Type	Example	Use
CHAR(5)	Hello	Fixed length text
VARCHAR(50)	Rahul Verma	Variable length text
TEXT	Long description	Large text

Example

CREATE TABLE users (
  name VARCHAR(30),
  email VARCHAR(50),
  bio TEXT
);

Date and Time Data Types

The data types for date and time store values derived from a time based representation.
So they are suitable for dates, timestamps, and schedules.

Data Type	Example	Use
DATE	2026-01-20	Date only
TIME	10:30:00	Time only
DATETIME	2026-01-20 10:30:00	Date and time
TIMESTAMP	2026-01-20 10:30:00	Tracks time

Example

CREATE TABLE orders (
  id INT,
  order_date DATE,
  order_time TIME
);

Boolean Data Type

The data type booleans are used to hold empty or true values.
Thus they are exactly perfect for a yes or no type fields.

Data Type	Example	Use
BOOLEAN	TRUE	Yes or no

Example

CREATE TABLE tasks (
  title VARCHAR(50),
  completed BOOLEAN
);

How to Choose the Right SQL Data Type

First, choose the data type that matches the data that you want to store.
Secondly, use numbers for counts and totals.
Next, require text for names and descriptions.
Lastly use date types for all other time relevant values.

Helps you to keep your database simple and manageable.

Summary

SQL datatypes determine how data is stored in a table.
As they prevent invalid values, they lead to fewer errors.
Learning SQL data types, then writing queries becomes easier.