Re: Kind of error-handler in a pgsql function

Thank you for your example.
I understand, in order to avoid inserting *duplicate keys*, first I try to update, when it fails make an insert. But other errors may occur, is there a possibility to distinguish between errors by an error-number.
Please can you tell me, where I can find system functions, variables like *diagnostics, row_count, found, and so on.....*
I studied the docu in http://www.ca.postgresql.org/devel-corner/docs/postgres/programmer.html, but I didn't find

Many thanks in advance
Irina

You must do it the other way around:

First, try update, then see how many records were updated, if there were 0
records updated, then do the insert.

Currently, plpgsql lacks decent exception handling.

Sample code:

create function ...
...
declare rec_affected int;
begin
update ...
get diagnostics rec_affected = ROW_COUNT;
if rec_affected = 0 then
insert ...
end if;
end;

On Wed, 4 Jul 2001, [iso-8859-1] DI Hasenöhrl wrote:

> Hi,
>
> When I write in psql:
> testdb=# update table1 set tableattribute='any' where table_nr=1;
> if a tuple exists, I get this message
> testdb=# update 1
> if no tuple with table_nr=1 exists, I get this message
> testdb=# update 0
>
>
> Is there a possibility to make a difference in a pgsql function like this:
> create function updTable(text,integer) returns int AS
> 'DECLARE
> msg ALIAS FOR $1;
> nr ALIAS FOR $2;
> BEGIN
> update table1 set tableattribute=msg where table_nr=nr;
> --pseudocode
> if update = 0 then
> return 0;
> else
> return 1;
> end if;
> END;
> 'language 'plpgsql';
>
> or for a function, which inserts data:
> create function insTable(text,integer) returns int AS
> 'DECLARE
> msg ALIAS FOR $1;
> nr ALIAS FOR $2;
> BEGIN
> insert into table1 values (nr,msg);
> --pseudocode
> if error= cannot insert duplicate key.....then
> return 0;
> else
> return 1;
> end if;
> END;
> 'language 'plpgsql';
>
> I want to know the result of an insert or update, because I call these functions from an Access form and the next steps of the program depend on these results.
>
> I hope, someone can help me, because I didn't find anything in the docu or mailing list.
> Thanks in advance
> Irina
>
> E-Mail: i(dot)hasenoehrl(at)aon(dot)at
>

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