PG Bug reporting form <noreply@postgresql.org> writes:
> select m.nome socio, p.tipo, sum(c.valor * m.percentual / 100) valor
> from contas_pagas('2019-04-01', '2019-04-30', 'R') c, medico m
> inner join planoconta p on (c.cod_planoconta = p.cod)
> where (m.percentual > 0)
> group by m.nome, p.tipo
> -- ERROR
> -- SQL Error [42P01]: ERROR: invalid reference to FROM-clause entry for
> table "c"
> -- Hint: There is an entry for table "c", but it cannot be referenced from
> this part of the query.
> In other words, we need to use cross join instead of put all tables in FROM
> clause, if one of these tables was a function that returns a table.
No, this has nothing to do with whether the relations are functions or
tables. You've forgotten that JOIN binds more tightly than comma in a
FROM-list, so that the relations available to that ON clause are only
m and p.
MySQL got this wrong for many years (maybe still does?), which has
encouraged a lot of confusion, but the SQL standard is entirely
clear on the point.
regards, tom lane