Обсуждение: Create table and update it within one function ?

Hi list !

I read in the manual that "Functions and trigger procedures are
always executed within a transaction established by an outer query".
Should I understand, that there is no way to make complex
procedures that would create tables AND fill them with data ?

I have a function that is defined as :
CREATE OR REPLACE FUNCTION my_function() RETURNS VOID AS $$
    SELECT create_graph_tables('graph', 'int8');
    UPDATE graph_edges SET cost=1;
$$ LANGUAGE SQL;


The create_graph_tables() function creates a table "graph_edges",
but when I run this 'CREATE FUNCTION' statement, I have an error
'relation "graph_edges" does not exist".

Is there no way to do this ?

Thanks a lot !
--
Arnaud

am  03.02.2006, um 12:58:19 +0100 mailte Arnaud Lesauvage folgendes:
> Hi list !
>
> I read in the manual that "Functions and trigger procedures are always
> executed within a transaction established by an outer query".
> Should I understand, that there is no way to make complex procedures that
> would create tables AND fill them with data ?
>
> I have a function that is defined as :
> CREATE OR REPLACE FUNCTION my_function() RETURNS VOID AS $$
>     SELECT create_graph_tables('graph', 'int8');
>     UPDATE graph_edges SET cost=1;
> $$ LANGUAGE SQL;
>
>
> The create_graph_tables() function creates a table "graph_edges", but when
> I run this 'CREATE FUNCTION' statement, I have an error 'relation
> "graph_edges" does not exist".

You should better use 'perform' instead 'select' in this function,
and execute 'UPDATE graph_e ...';

I have a simple example:

create or replace function foo (varchar) returns int as $$
begin
        execute 'create table ' || $1 || '(id int, cost int);';
        return 1;
end;
$$ language plpgsql;


create or replace function foo2 () returns void as $$
begin
        perform foo('graph');
        execute 'insert into graph values (1,10);';
        execute 'UPDATE graph SET cost=1;';
end;
$$ language plpgsql;


test=# \d graph;
Did not find any relation named "graph".
test=# select foo2();
 foo2
------

(1 row)

test=# select * from graph ;
 id | cost
----+------
  1 |    1
(1 row)




HTH, Andreas
--
Andreas Kretschmer    (Kontakt: siehe Header)
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A. Kretschmer a écrit :
 > > You should better use 'perform' instead 'select' in this
function,
 > > and execute 'UPDATE graph_e ...';

Andreas, it works great !
Thanks for your help *again* !

Regards
--
Arnaud