From: Richard Huxton <dev@archonet.com>
To: Amitabh Kant <amitabhkant@gmail.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Referencing external table in update/insert triggers
Date: Thu, 18 Feb 2010 09:23:16 +0000
Message-ID: <4B7D0704.70301@archonet.com> (raw)
In-Reply-To: <84b68b3d1002170718s5da61fam69de31ad1e54595f@mail.gmail.com>
References: <84b68b3d1002170718s5da61fam69de31ad1e54595f@mail.gmail.com>
On 17/02/10 15:18, Amitabh Kant wrote:
>
> CREATE OR REPLACE FUNCTION update_data() RETURNS TRIGGER AS $update_data$
> BEGIN
> IF NEW.t1f4> t2.t2f4
> UPDATE t2 set t2f2=NEW.t1f2, t2f3=NEW.t1f3, t2f4=NEW.t1f4 where
> t2f1=NEW.d1;
> RETURN NEW;
> END IF;
> END;
> $update_data$ LANGUAGE plpgsql;
> I would like to compare the date present in the t2f4 with the new data being
> updated through the trigger. Using the if line as listed above returns an
> error.
You can always do something like:
SELECT t2.t2f4 INTO my_variable FROM t2 WHERE ...
IF NEW.t1f4 > my_variable
However, for this case you can just do an update with an extended where
clause:
UPDATE t2 ... WHERE t2f1=NEW.d1 AND NEW.t1f4 > t2.t2f4
No need for the IF.
--
Richard Huxton
Archonet Ltd
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To: pgsql-sql@postgresql.org
Cc: dev@archonet.com, amitabhkant@gmail.com
Subject: Re: Referencing external table in update/insert triggers
In-Reply-To: <4B7D0704.70301@archonet.com>
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