PostgreSQL COALESCE() Function

Syntax

COALESCE(value1, value2, ...)

Basic Example

SELECT COALESCE(nickname, first_name, 'Unknown') AS display_name
FROM users;

When to use it

Use COALESCE when you need a null 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 IFNULL() Function
• MySQL COALESCE() Function
• MySQL NULLIF() Function
• PostgreSQL CONCAT() Function
• PostgreSQL STRING_AGG() Function
• PostgreSQL SPLIT_PART() Function

FAQ

Is COALESCE 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.