Re: plpgsql errorcodes

hi,

i want the DB functionality to be done by the server. this means i want to
write functions like

CREATE FUNCTION insert_any(....) RETURNS INT AS '
BEGIN

END; '
LANGUAGE 'plpgsql'

returning an errorcode so i can map this errorcode to a message for the user
of the client. and i want to do this on the server without using any
special java or php command on the client side.

the only thing postgreSQL returns - if an error occured - is a textual
message you cant use for telling the user what happend.

one thing i want to know - inside the function - is why postgre stopped
working. something like

num := CAST($1 AS INT);
IF ERROR THEN RETURN -3; END IF; -- "cannot convert to integer"

because i do not want to reenvent the wheel. if there is a conversion
function i want to use it, and i want to know if or why it failed.

besides i have written simple type checking functions doing the following

// php

$ret = pg_call("SELECT checkInteger('abc')");
if ($ret != 0) $msg = pg_call("SELECT getErrorMessage($ret,'german')");
else ...

i can use the same functions in every client program (java, VB, C ..).
but i think it is absurd to do the same thing twice. postgre checks it also
in the CAST
statement. the only thing i want to know is what happend. even a parseable
errorcode
like

ERROR(23890) : 'invalid numeric format'

or

ERROR(100) constraint 'myConstraintName '

would be helpfull

is there ANY possibility to catch errorcodes in plpqsql ?
is there ANY possibility to catch errorcodes otherwise ?

i am using postgreSQL 7.4

thanx

Sepp

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begin "Robert Wimmer" <seppwimmer(at)hotmail(dot)com> wrote:
> i want the DB functionality to be done by the server. this means i want to
> write functions like

> CREATE FUNCTION insert_any(....) RETURNS INT AS '
> BEGIN

> END; '
> LANGUAGE 'plpgsql'

> returning an errorcode so i can map this errorcode to a message for the user
> of the client. and i want to do this on the server without using any

You can use RAISE to generate a error.

end
Andreas
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>From: Andreas Kretschmer <andreas_kretschmer(at)despammed(dot)com>
>To: pgsql-interfaces(at)postgresql(dot)org
>Subject: Re: [INTERFACES] plpgsql errorcodes
>Date: Fri, 17 Dec 2004 17:52:00 +0100
>
>begin "Robert Wimmer" <seppwimmer(at)hotmail(dot)com> wrote:
> > i want the DB functionality to be done by the server. this means i want
>to
> > write functions like
>
> > CREATE FUNCTION insert_any(....) RETURNS INT AS '
> > BEGIN
>
> > END; '
> > LANGUAGE 'plpgsql'
>
> > returning an errorcode so i can map this errorcode to a message for the
>user
> > of the client. and i want to do this on the server without using any
>
>You can use RAISE to generate a error.
>
>end
>Andreas

hi andreas,

RAISE NOTICE wouldnt help, because it would never be executed if a runtime
error occurs. a short example.

CREATE TABLE dummy (
id SERIAL ...
name VARCHAR(20) ,
code INT CONSTRAINT codeNotUnique UNIQUE,
first DATE);

-- this function controls data before inserting
CREATE FUNCTION insert_dummy(TEXT, TEXT, TEXT) RETURNS INTEGER AS '
DECLARE dat DATE;
BEGIN
dat := CAST($3 AS DATE);
-- if an error occurs execution will be stopped i cant drop any notice
-- i would like todo something like
if ERROR != 0 THEN RETURN -1; END IF; -- cannot convert to date
INSERT INTO dummy(name, code, first) VALUES($1,$2,$3);
if CONSTRAINT-ERROR = codeNotUnique THEN RETURN -2 END IF;
-- you cant do that, you have to do the following
-- the SELECT will be done again internal from psql
SELECT INTO tmp * FROM dummy WHERE code = CAST($2 AS INTEGER);
IF FOUND THEN RETURN -2 END IF;
-- everything is OK
RETURN 0;
END; '
LANGUAGE plpgsql;

my problem is, all plpgsql does is fine. but you do not get any errorcode
during the function.
and outside the function the errormessages cannot be used the generate a
usefull errorcode.
its just some english text.

i hope you can understand what i am talking about,

bye sepp

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"Robert Wimmer" <seppwimmer(at)hotmail(dot)com> writes:
> my problem is, all plpgsql does is fine. but you do not get any errorcode
> during the function.

I'm afraid you're stuck. At some point we're going to extend RAISE to
allow you to specify a SQLSTATE code, but it didn't get done for 8.0.

regards, tom lane