Re: [SQL] No DIVIDE Operator
| От | Chris Bitmead |
|---|---|
| Тема | Re: [SQL] No DIVIDE Operator |
| Дата | |
| Msg-id | 372DBA88.CCBD5EF3@bigfoot.com обсуждение исходный текст |
| Ответ на | No DIVIDE Operator (Joerg Fischer <fischer@zkm.de>) |
| Ответы |
Re: [SQL] No DIVIDE Operator
|
| Список | pgsql-sql |
Joerg Fischer wrote:
>
> Chris Bitmead wrote:
> >
> > Isn't that what EXCEPT does?
>
> Maybe the operator is named differently between different database
> systems. Anyway, as far as I am concerned, PGSQL lacks it. Or
> (hopefully), am I wrong??
Well Postgres has EXCEPT. Is that what you want?
>
> Regards
>
> Joerg Fischer
>
> > chris=> create table foo (text text);
> > CREATE
> > chris=> insert into foo values('aaa');
> > INSERT 22153 1
> > chris=> insert into foo values('bbb');
> > INSERT 22154 1
> > chris=> insert into foo values('ccc');
> > INSERT 22155 1
> > chris=> select * from foo EXCEPT select 'aaa';
> > text
> > ----
> > bbb
> > ccc
> > (2 rows)
> >
> > > If there would be a divide operator, I could write
> > >
> > > select name, prename from Person divide select name, prename from
> > > Officer;
> > >
> > > without it, however, things get really complicated:
> > >
> > > select name, prename from Person where prename not in ( select prename
> > > from Officer where Officer.name = Person.name );
> > >
> > > This is an easy example. However, I have to deal with about 10 tables in
> > > a corresponding way.
> > >
> > > Any better idea? Will there be a divide operator in PGSQL soon?
> > >
> > > Thanks!
> > >
> > > Regards
> > >
> > > Joerg Fischer
--
Chris Bitmead
http://www.bigfoot.com/~chris.bitmead
mailto:chris.bitmead@bigfoot.com
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