Is Coalesce a function of ANSI SQL

Question

Is the COALESCE a function of the ANSI SQL especification? Is it supported by the major relational databases?

Answer 1

Yes:

https://www.mssqltips.com/sqlservertip/2689/deciding-between-coalesce-and-isnull-in-sql-server/

From the article:

Some think that you need to use COALESCE because it is the only one that adheres to the ANSI SQL standard.

and Yes.

Answer 2

The ISO/ANSI SQL standard specification (ISO/IEC 9075-2:2016(E)) lists CASE and COALESCE as optional features:

F261     CASE expression
F261-04  COALESCE