Re: psql - user defined SQL variables

From: Jean-Luc Lachance <jllachan(at)sympatico(dot)ca>
To: Grainne Reilly <greilly1(at)comcast(dot)net>
Cc: David Fetter <david(at)fetter(dot)org>, pgsql-general(at)postgresql(dot)org
Subject: Re: psql - user defined SQL variables
Date: 2004-08-18 20:45:57
Message-ID: 4123C005.9070000@sympatico.ca
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What do you mean varables do not exists?
Ever heard of SELECT INTO?

Grainne Reilly wrote:
> Thanks for the response - pity PostgreSQL doesn't have this. These are a
> bunch of quick and dirty data population scripts which I was hoping to
> avoid rewriting to use temporary tables, subselects etc.
> It is a useful feature for these kind of scripts (Sybase has it and it
> has always had subselects) - and in Oracle I can use an anonymous PL/SQL
> block to declare and use variables directly in sqlplus.
> Are there any plans for PostgreSQL to support anonymous PL/pgSQL blocks
> directly in psql - now that would be very nice!
> Thanks again.
> Grainne.
>
>
> At 01:48 AM 8/18/2004, David Fetter wrote:
>
>> On Wed, Aug 18, 2004 at 12:22:27AM -0400, Grainne Reilly wrote:
>> > I am new to PostgreSQL and am porting some scripts written for MySQL
>> > over to psql.
>>
>> The least work you'll do here is to refactor your app entirely.
>>
>> PostgreSQL will just plain handle about 3/4 of what you used to have
>> to deal with up in middleware land. It also supports all kinds of
>> wizardry that will astound you as you run across it. :)
>>
>> > There is one MySQL feature which I cannot find in psql - user
>> > defined SQL variables. In MySQL I can use these to hold the result
>> > (numeric, string or null) of a select: e.g. select @count =
>> > count(*) from mytable;
>>
>> This is a MySQLism to work around their lack of subselects. But if
>> that turns out not to be enough, you have a broad choice of procedural
>> languages, from the ADA-like PL/PgSQL to PL/Perl, PL/Python and (soon)
>> PL/PHP.
>>
>> > Thanks in advance for any suggestions,
>>
>> See about redoing your app. It will be less work than trying to graft
>> the MySQL design onto PostgreSQL, which is about like trying to hook
>> an ox cart to a jet engine :)
>>
>> Cheers,
>> D
>> --
>> David Fetter david(at)fetter(dot)org http://fetter.org/
>> phone: +1 510 893 6100 mobile: +1 415 235 3778
>>
>> Remember to vote!
>>
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