Re: Coalesce bug ?

Поиск
Список
Период
Сортировка
От Kevin Grittner
Тема Re: Coalesce bug ?
Дата
Msg-id 20121221162408.144640@gmx.com
обсуждение исходный текст
Список pgsql-general
David Johnston wrote:

> I thought that in order to call the Coalesce function the system
> would have to know the value of all parameters. There is no lazy
> instantiation in SQL.

Tom already addressed the main question, but I want to clarify this
point. COALESCE is not a function; it is defined by the standard as
a short form of a CASE statement. The syntax just makes it look
similar to a function. As a CASE statement, it stops when it finds
the right (non-NULL) case.

-Kevin


В списке pgsql-general по дате отправления:

Предыдущее
От: ERR ORR
Дата:
Сообщение: Question about indexes and operator classes
Следующее
От: "David Johnston"
Дата:
Сообщение: Re: Coalesce bug ?