Re: Fwd: Re: sum(bool)?
От | darcy@druid.net (D'Arcy J.M. Cain) |
---|---|
Тема | Re: Fwd: Re: sum(bool)? |
Дата | |
Msg-id | 20010225235403.2F8E81A62@druid.net обсуждение исходный текст |
Ответ на | Fwd: Re: sum(bool)? ("J.Fernando Moyano" <txinete@wanadoo.es>) |
Список | pgsql-sql |
Thus spake J.Fernando Moyano > El Viernes 23 Febrero 2001 16:22, escribiste: > > i want to add up the "true" values of a comparison like > > > > sum(a>b) > > > > it just doesn't work like this > > > > any workaround? > > I did exactly the same thing two months ago .... > > I created this tiny function: > > CREATE FUNCTION bool2int(bool) RETURNS integer > AS 'select (case when $1=true then 1 else 0 end)' > LANGUAGE 'sql'; > > > You can do: sum(bool2int(a>b)) > > easy ??? ;-)) Almost as easy as "SELECT COUNT(*) FROM table WHERE a > b" -- D'Arcy J.M. Cain <darcy@{druid|vex}.net> | Democracy is three wolves http://www.druid.net/darcy/ | and a sheep voting on +1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.
В списке pgsql-sql по дате отправления: