From: Josh Berkus <josh@agliodbs.com>
To: Rajesh Kumar Mallah <mallah@trade-india.com>
To: pgsql-sql@postgresql.org
Subject: Re: Getting NEW and OLD in ordinary functions.
Date: Wed, 9 Apr 2003 09:45:45 -0700
Message-ID: <200304090945.45334.josh@agliodbs.com> (raw)
In-Reply-To: <200304091551.02277.mallah@trade-india.com>
References: <200304091551.02277.mallah@trade-india.com>
Rajesh,
> is it possible to access NEW , OLD rows in an ordinary function
> (function which are not TRIGGER PROCEDURES)
I do this all the time in a roundabout way.
1) I create a function that takes all the columns of the table as parameters.
2) Instead of doing an UPDATE or INSERT into the table, the client calls this
function.
3) I check all the data fed to the function. If I need to compare it to the
data on disk, I SELECT the "old" data into a RECORD and compare.
4) If everything's ok, I do an UPDATE or INSERT.
I have about 10,000 lines of PL/PgSQL doing this for various applications
where the data integrity logic is too complex for a trigger or check
constraint. It also allows me to implement a custom locking scheme and
return custom error messages. It works very well.
--
Josh Berkus
Aglio Database Solutions
San Francisco
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To: pgsql-sql@postgresql.org
Cc: josh@agliodbs.com, mallah@trade-india.com
Subject: Re: Getting NEW and OLD in ordinary functions.
In-Reply-To: <200304090945.45334.josh@agliodbs.com>
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