Re: Kind of error-handler in a pgsql function

There is _no error handling_ in plpgsql

You can find documentation at:
http://www.postgresql.org/idocs/index.php?plpgsql.html

On Thu, 5 Jul 2001, [iso-8859-1] DI Hasenhrl wrote:

> 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 Hasenhrl 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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