Re: [HACKERS] Views on aggregates - need assistence

On Mon, 23 Feb 1998, Bruce Momjian wrote:

> >
> > On Mon, 23 Feb 1998, Bruce Momjian wrote:
> >
> > > Actually, it does handle unions of views, but not views of unions.
> > > Informix doesn't support it either, and I don't know what the other
> > > dbms's do, but I think I am going to find out soon from someone. :-)
> >
> > What exactly would you like me to try here? *raised eyebrow*
> >
> >
> >
>
>
> create view as
> select oid from pg_user union select oid from pg_class
>
> or something like that. That will not work under PostgreSQL. But you
> can use views as part of a union:
>
> select oid from view1
> union
> select oid from view2

You mean like:

SQL> select * from one
2 ;

A
----------
3
4
2

SQL> create table two ( B int );

Table created.

SQL> insert into two values ( 1 );

1 row created.

SQL> insert into two values ( 2 ) ;

1 row created.

SQL> insert into two values ( 3 ) ;

1 row created.

SQL> create view v1 as select A from one union select B from two;

View created.

SQL> select * from v1;

A
----------
1
2
3
4