sum grouping with NULL/ Not null

Simple -
select sum(x) from (select null x from dual union all (select 1 x from dual)). The result is 1
But sum(null+1) is Null.

non ANSI?

SQL Reference

Aggregate Functions

All aggregate functions except COUNT(*) and GROUPING ignore nulls.

Clark Pokejn

Simple - select sum(x) from (select null x from dual union all (select 1 x from dual)). The result is 1 But sum(null+1) is Null. non ANSI?

Подсказка: NULL + 1 = NULL.

- Групповая функция SUM пропускает NULL значения.
- NULL + 1 <> select sum(x) from (select null x from dual union all select 1 x from dual)