PostgreSQL JSON_AGG() Function

Syntax

JSON_AGG(expression)

Basic Example

SELECT JSON_AGG(total) AS result
FROM orders;

When to use it

Use JSON_AGG when you need a aggregate operation in PostgreSQL. This page is designed as a quick reference for developers, analysts, and students comparing SQL dialects.

Common mistake

A common mistake is copying syntax from another SQL dialect. Always verify function name, argument order, and formatting tokens for PostgreSQL.

Related SQL Functions

• MySQL COUNT() Function
• MySQL SUM() Function
• MySQL AVG() Function
• MySQL MIN() Function
• MySQL MAX() Function
• MySQL GROUP_CONCAT() Function

FAQ

Is JSON_AGG available in every SQL database?

Not always. Function names and argument behavior can differ across SQL engines.

Can I use this in SELECT queries?

Yes. Most SQL functions are commonly used in SELECT and often in WHERE, ORDER BY, and GROUP BY depending on the function.