Hello, as per documentation <https://www.postgresql.org/docs/current/functions-conditional.html#FUNCTIONS-COALESCE-NVL-IFNULL> > The COALESCE function returns the first of its arguments that is not null. Null is returned only if all arguments are null.
This is not exactly true. In fact: The COALESCE function returns the first of its arguments that *is distinct* *from *null. Null is returned only if all arguments *are not distinct from* null. See my stack overflow question here <https://stackoverflow.com/questions/78691097/postgres-null-on-composite-types> . Long story short select coalesce((null, null), (10, 20)) as magic; returns magic ------- (,) (1 row) However, this is true: select (null, null) is null; -- *Ing. Ondřej Navrátil, Ph.D.* IT Analytik M +420 728 625 950 E onavratil@monetplus <onavra...@monetplus.cz>.cz <onavra...@monetplus.cz> MONET+,a.s., Za Dvorem 505, 763 14 Zlín-Štípa monetplus.com <https://www.monetplus.cz/> | linkedin <https://www.linkedin.com/company/monetplus/> | facebo <https://www.facebook.com/monetplus/>ok <https://www.facebook.com/monetplus/>
