Message-ID: <1461.219.65.233.94.1049915353.squirrel@mail.trade-india.com>
Date: Thu, 10 Apr 2003 00:39:13 +0530 (IST)
Subject: Re: Getting NEW and OLD in ordinary functions.
From: <mallah@trade-india.com>
To: <josh@agliodbs.com>
In-Reply-To: <200304091123.16123.josh@agliodbs.com>
References: <200304091551.02277.mallah@trade-india.com>
	<200304090945.45334.josh@agliodbs.com>
	<1321.219.65.233.94.1049911417.squirrel@mail.trade-india.com>
	<200304091123.16123.josh@agliodbs.com>
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Cc: <pgsql-sql@postgresql.org>
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> Rajesh,
>
>> could u pleeeeeez check my 50 LOC  when u have some free time and commen=
t on my  questions I
>> will be really grateful.
>
> SInce you asked so nicely ...

Glad to hear again!

>
> I don't see anything wrong with your code, though I will of course be hap=
py to  help with
> particular errors.  And your general approach is fine.
>
> Two suggestions for improvement:
>
> 1)
>
>> This is also very interesting , when u time can u discuss it a bit more.=
 what does the locking
>> scheme achieve?
>> and how does "custom error messages " really help ?
>> (maybe in a pvt mail if its not appropriate here)
>
> This will be the subject for an "Adventures in PostgreSQL" article if I e=
ver  get my website up
> ...
>
>        IF listing_status NOT IN (''ACTIVE'', ''DELETED'',
> ''EXPIRED_BY_SYSTEM'') THEN
>                RAISE EXCEPTION '' listing_status has to be ACTIVE,DELETED=
 or
> EXPIRED_BY_SYSTEM for profile_id=3D%'' , profile_id;
>        END IF ;
>
>        IF hosting_status NOT IN (''TEMPORARY'', ''COMPLETE'') THEN
>                RAISE EXCEPTION '' hosting_status has to be TEMPORARY or
> COMPLETE for profile_id=3D%'' , profile_id;
>        END IF ;
>
> These two constraints might be better handled by Foriegn Keys to an  appr=
opriate reference list
> (personally, I don't use check constraints at all  ... I find FKs vastly =
easier to manage.)

This was for simulating CHECK (column in ('A','B' , 'C')) ;

I already have 5 FKEYS  on that table dont' u feel fkeys  for this
purpose is an overkill?
eg here the valid values can range from say 3 to 10 (small number)
whereas FKEYS are capable to check in a very large set residing in
another table.
also fkeys makes updates and inserts slower  (i feel)

another question i have seen CHECK traslating IN to a set of ORs
does the same happen in pl/pgsql internally?  and does it really matter
for here for small target sets?

>
> Second, it would be more user-friendly if you concatinated all error mess=
ages  and delivered a
> list of *all* problems to the user in the exception message,  rather than=
 one at a time.

Thanks for this ,

> Imagine a user who fixed his listing status,  only to get an error messag=
e about hosting
> status, and then to get an error  message about online sales.

true this is particularly valid in www environments.

Regds
MAllah.
>
>
> --
> -Josh Berkus
> Aglio Database Solutions
> San Francisco


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