Re: Catching DML exceptions in PL/pgSQL

Radu-Adrian Popescu wrote:
> .....................
> begin
> _res.code:=1;
> select id into iid from log where id=_id;
> if not found then begin
> _res.msg:=''insert'';
> *insert into log (log, data) values (_log, _data);
> if not found* then begin
> _res.msg:=_res.msg || '' error'';
> _res.code:=-1;
> end;
> end if;
> end;
> else begin
> .....................
> The thing is if _data (parameter) is null and table has a (data <> null) check,
> the insert would fail and abort the function before my "if not found" test.

You could test for _data is null, and if so check attnotnull in
pg_attribute. E.g. something like:

declare
iattnotnull bool
[...]
begin
if _data is null then
select into iattnotnull attnotnull from pg_catalog.pg_attribute
where attrelid = 'log'::regclass and attname = 'data';
if iattnotnull then
_res.code := -1;
[...]

> Is there anything I can do to make sure the function always returns _res ?
> Something along the lines of Oracle's exception handling, or the @@error trick
> in mssql ?

There is currently no way to "catch" the exception in PL/pgSQL, but
maybe the above would work for you.

HTH,

Joe