From: eVl One <evl@my-mail.com.ua>
To: Bruno Wolff III <bruno@wolff.to>
Cc: pgsql-sql@postgresql.org
Subject: Re: How to check: is some key referenced from sometable
Date: Sun, 10 Aug 2003 00:44:32 +0300
Message-ID: <18618711976.20030810004432@my-mail.com.ua> (raw)
In-Reply-To: <20030809150809.GA22927@wolff.to>
References: <3159.195.5.48.107.1059985076.squirrel@my-mail.com.ua>
<20030809150809.GA22927@wolff.to>
Hello, Bruno.
You wrote 9 08 2003, 18:08:09:
BWI> On Mon, Aug 04, 2003 at 11:17:56 +0300,
BWI> evl@my-mail.com.ua wrote:
>> Please help.
>>
>> Need a boolean function which returns true if given key in table is
>> referensed from another table(s).
BWI> Use "exists" with a subselect. Something like:
BWI> select exists(select 1 from table where table.key = 'value');
Thanx for advice, but way I know and it can't be used.
That's why I've got too many and/or too big tables from which
such key is referenced. I mean (in some simplified way):
table A ( -- main table A
id SERIAL,
PRIMARY KEY(id)
);
tableBxx ( -- a lot of tables which got a.id as FOREIGN KEY
... -- too much to check 'em all with EXISTS queries
a_id int4 REFERENCES a(id), -- without significant perfomance loss
...
);
So I need:
"silent delete" - i.e. when trying to DELETE row from A I'll not fall
out with "$1 referential integrity violation - key in A still
referenced from Bxx", but silently doesn't delete row ('cause run
it from function and need function to executes farther after delete);
"something to check reference" - system (potgresql) is very quickly
realizes that key is referenced from another table, maybe this
information may be accessed through some system relations, or so?
Thanx for attention.
--
Best regards,
eVl
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To: pgsql-sql@postgresql.org
Cc: evl@my-mail.com.ua, bruno@wolff.to
Subject: Re: How to check: is some key referenced from sometable
In-Reply-To: <18618711976.20030810004432@my-mail.com.ua>
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