Thread: Private or publice function

Private or publice function

From
Nirmalya Lahiri
Date:
Hi,
 How can I create a publice or private function?

Nirmalya Lahiri



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Re: Private or publice function

From
Richard Huxton
Date:
Nirmalya Lahiri wrote:
> Hi,
>  How can I create a publice or private function?

I'm not sure the concept makes sense in PostgreSQL. Can you explain what
you're trying to achieve?

--
   Richard Huxton
   Archonet Ltd

Re: Private or publice function

From
Richard Huxton
Date:
Nirmalya Lahiri wrote:
> Thanks Richard,
>  for your reply. Now I am explaining you what I want.
> Let I have 4
> functions......function_1(),function_2(),function_3(),function_4().
[snip]
>  Now after creating these functions, I can easily call every function
> from psql prompt. But I want to encapsulate function_2() and
> function_3() withen function_1(), so that no one can call
> function_2() and function_3() from psql prompt and from function_4(),
> only from withen the function_1() I can call function_2() and
> function_3().
>
>  Is it possible in PostgreSQL?

Not elegantly - plpgsql only has PostgreSQL's naming and permissions
structure to use. Perhaps the simplest is to create a schema "private"
only accessible to user "U1". Place function2(),function(3) in schema
"private".
Place function1() in the public schema, making sure you create it as
user "U1" and mark it "SECURITY DEFINER".

So - everyone can execute function1(), but only user U1 can run
function2()/3(). Since function1() runs as user U1 everything should
just work.

--
   Richard Huxton
   Archonet Ltd

Re: Private or publice function

From
Nirmalya Lahiri
Date:
Thanks Richard,
 for your reply. Now I am explaining you what I want.
Let I have 4
functions......function_1(),function_2(),function_3(),function_4().


create or replace function function_1() returns numeric as '
begin
 create or replace function function_2() returns numeric as ''
 begin
  --------
  --------
 end;
 '' language plpgsql
 -----------
 -----------
 -----------
 create or replace function function_3() returns numeric as ''
 begin
  ---------
  ---------
 end;
 '' language plpgsql
end ;
' language plpgsql



create or replace function function_4() returns numeric as '
begin
 -----------
 -----------
end;
' language plpgsql


 Now after creating these functions, I can easily call every function
from psql prompt. But I want to encapsulate function_2() and
function_3() withen function_1(), so that no one can call
function_2() and function_3() from psql prompt and from function_4(),
only from withen the function_1() I can call function_2() and
function_3().

 Is it possible in PostgreSQL?

Nirmalya Lahiri


--- Richard Huxton <dev@archonet.com> wrote:

> Nirmalya Lahiri wrote:
> > Hi,
> >  How can I create a publice or private function?
>
> I'm not sure the concept makes sense in PostgreSQL. Can you explain
> what
> you're trying to achieve?
>
> --
>    Richard Huxton
>    Archonet Ltd
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 2: you can get off all lists at once with the unregister
> command
>     (send "unregister YourEmailAddressHere" to
> majordomo@postgresql.org)
>




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Re: Private or publice function

From
Bruno Wolff III
Date:
On Tue, Jan 11, 2005 at 18:36:17 +0000,
  Richard Huxton <dev@archonet.com> wrote:
> Nirmalya Lahiri wrote:
> >Thanks Richard,
> > for your reply. Now I am explaining you what I want.
> >Let I have 4
> >functions......function_1(),function_2(),function_3(),function_4().
> [snip]
> > Now after creating these functions, I can easily call every function
> >from psql prompt. But I want to encapsulate function_2() and
> >function_3() withen function_1(), so that no one can call
> >function_2() and function_3() from psql prompt and from function_4(),
> >only from withen the function_1() I can call function_2() and
> >function_3().
> >
> > Is it possible in PostgreSQL?
>
> Not elegantly - plpgsql only has PostgreSQL's naming and permissions
> structure to use. Perhaps the simplest is to create a schema "private"
> only accessible to user "U1". Place function2(),function(3) in schema
> "private".
> Place function1() in the public schema, making sure you create it as
> user "U1" and mark it "SECURITY DEFINER".
>
> So - everyone can execute function1(), but only user U1 can run
> function2()/3(). Since function1() runs as user U1 everything should
> just work.

This is the right idea, but you can do it more elegantly using the
EXECUTE privilege for functions. Postgres grants EXECUTE access to
PUBLIC by default for functions, as they are usually meant to be
public. But you can revoke that access and use the scheme above without
needing to futz with schemas.