Обсуждение: variables in ad hoc queries

If I have a function that returns an integer, how can I use the
following code outside of a function block?

declare
_myint int;

begin
_myint := myfunction( );
end;


or is it just not possible?

Iain

On Tue, Sep 29, 2009 at 8:06 AM, Iain Barnett <iainspeed@gmail.com> wrote:
> If I have a function that returns an integer, how can I use the following
> code outside of a function block?
>
> declare
> _myint int;
>
> begin
> _myint := myfunction( );
> end;

you can...all postgresql functions can be used in queries:

select * from myfunction();

What you are probably bumping into is that previously to 8.4, plpgsql
functions could not be called the short way:
select myfunction();

If this is your problem, the workarounds are to adjust the query, wrap
it with an sql function, or upgrade to 8.4.

merlin

On 29/09/2009 13:06, Iain Barnett wrote:
> If I have a function that returns an integer, how can I use the
> following code outside of a function block?
>
> declare
> _myint int;
>
> begin
> _myint := myfunction( );
> end;

You can't use this code outside of a function - this just isn't valid
SQL. You can of course use your function -

  select myfunction();

- though I'm sure you know that already.


What exactly are you trying to achieve?


Ray.


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2009/9/29 Iain Barnett <iainspeed@gmail.com>:
> If I have a function that returns an integer, how can I use the following
> code outside of a function block?
>
> declare
> _myint int;
>
> begin
> _myint := myfunction( );
> end;
>

select myfunction from myfunction();

or, you can use the function in SQLs wherever you'd usually use an integer

> or is it just not possible?
>
> Iain
>
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Sorry, in oversimplifying for clarity I was making it more unclear!

Whenever I write a function, I like to write a quick ad hoc test to
go with it in the comments. It means I can also test combinations of
functions together quickly, without having to build other functions
first, and gives anyone reading the function a quick idea of the type
of inputs/outputs they might see. I've mostly worked with SQL Server,
and with that I can write statements that might need to be within a
function in ad hoc fashion.

A common example is when I write an insert statement that returns the
primary key of the inserted row. I'd like to capture that in a
variable and run it through other functions. To be able to declare
variables outside a function would be helpful in this respect.

It's just a quick way to an easy test, in my view, but if it's not
possible then that's ok, I'll just write full blown test functions
from the start.


Regards,
Iain