SQL - Introduction to JSON in SQL

JSON (JavaScript Object Notation) is a lightweight data format used to store and exchange data. Modern SQL databases like MySQL, PostgreSQL, and SQL Server provide built-in support to store and query JSON data efficiently.

Using JSON in SQL allows developers to store semi-structured data inside a relational database without creating many tables.

Why Use JSON in SQL?

• To store flexible or dynamic data
• To handle API responses easily
• To reduce complex table structures
• To manage nested data inside a single column

JSON Data Type

Most modern databases support a special JSON data type that validates JSON format automatically.

Example:

CREATE TABLE users (

  id INT,

  profile JSON

);

Common JSON Functions

• JSON_EXTRACT() – Get data from JSON
• JSON_OBJECT() – Create JSON object
• JSON_ARRAY() – Create JSON array
• JSON_SET() – Update JSON value

Simple Example

SELECT JSON_EXTRACT(profile, '$.name')

FROM users;

This query extracts the name from the JSON column.

Conclusion

JSON in SQL combines the power of relational databases with the flexibility of NoSQL. It is widely used in modern web and backend applications for storing structured and semi-structured data efficiently.