Thread: AW: AW: SQL3 UNDER

> > When calling functions with a class argument they do pass 
> all attributes
> > of subclasses to it. They use late function binding, so you 
> can define
> > different functions for different subclasses having the same name.
> > They only show parent columns when doing 'select * from 
> class' that has
> > subclasses.
> 
> That's what we are planning also, to return all columns current 
> favourite syntax to use is 'select ** from class', but even it is not 
> yet implemented.

I am not talking about select * I am talking about
"select somefunc(supertable) from supertable"

create table supertable  (a int);
create table taba (b int) under supertable;

create function somefunc (tup supertable) returning int
as 'select 1' ...

create function somefunc (tup taba) returning int
as 'select 0.5*b' ....

> 
> BTW, does Informix/Illustra do single or multiple inheritance 
> with their
> UNDER?

Multiple, as I said they took Illustra (which was a parallel effort
to port Postgres to SQL). 

Andreas

Zeugswetter Andreas SB wrote:
> 
> > > When calling functions with a class argument they do pass
> > all attributes
> > > of subclasses to it. They use late function binding, so you
> > can define
> > > different functions for different subclasses having the same name.
> > > They only show parent columns when doing 'select * from
> > class' that has
> > > subclasses.
> >
> > That's what we are planning also, to return all columns current
> > favourite syntax to use is 'select ** from class', but even it is not
> > yet implemented.
> 
> I am not talking about select * I am talking about
> "select somefunc(supertable) from supertable"
> 
> create table supertable  (a int);
> create table taba (b int) under supertable;
> 
> create function somefunc (tup supertable) returning int
> as 'select 1' ...
> 
> create function somefunc (tup taba) returning int
> as 'select 0.5*b' ....

So how does this work in Informix/Illustra ?

i.e. is the binding done at row evaluation time or 
"when they do 'select * ...' and don't know about coumn b"

> >
> > BTW, does Informix/Illustra do single or multiple inheritance
> > with their
> > UNDER?
> 
> Multiple, 

That's what I thought ;)

> as I said they took Illustra (which was a parallel effort
> to port Postgres to SQL).

That much I know (we almost bought an Illustra db before Postgres95 
was even available;)

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Hannu