From greg at technomadic.org  Wed May  9 17:27:36 2012
From: greg at technomadic.org (Greg Pfeil)
Date: Wed, 9 May 2012 11:27:36 -0600
Subject: [postmodern-devel] single-key object magic
Message-ID: <66BD02CD-2571-4F6A-8FE3-F85840172B5C@technomadic.org>

I've made a few changes to Postmodern. They both try to do a little magic in the case where a table has a single primary key column. The first change allows you to use a DAO-OBJECT directly as a parameter, rather than pulling out the key field. EG:

> (select-dao 'foo (:= 'bar bar))

instead of having to do

> (select-dao 'foo (:= 'bar (id bar)))

And the second allows the use of a DAO-CLASS name in the :COL-TYPE field of a slot definition. EG:

> (defclass bar () ((id :col-type serial)) (:metaclass dao-class))
> (defclass foo () ((bar :col-type (or db-null bar))) (:metaclass dao-class))

instead of

> (defclass bar () ((id :col-type serial)) (:metaclass dao-class))

> (defclass foo () ((bar :col-type (or db-null integer))) (:metaclass dao-class))


These both seem pretty basic, but they mean that you can change the primary key column name or type without having to make changes throughout your code. Also, I see it as a first step toward being able to (eagerly or lazily) auto-populate slots with full objects rather than keys.

Does this seem useful, too magical, or already there but I missed it?

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From marijnh at gmail.com  Wed May  9 18:30:29 2012
From: marijnh at gmail.com (Marijn Haverbeke)
Date: Wed, 9 May 2012 20:30:29 +0200
Subject: [postmodern-devel] single-key object magic
In-Reply-To: <66BD02CD-2571-4F6A-8FE3-F85840172B5C@technomadic.org>
References: <66BD02CD-2571-4F6A-8FE3-F85840172B5C@technomadic.org>
Message-ID: <CAJnHWXtcCF1GQ-Xpcs8oD-Sdn3E+ptWX4qziK39XTb7hDELf4Q@mail.gmail.com>

Hello Greg,

I'm hesitant to incorporate any 'magic' like this into the core
library. It's a matter of aesthetics, but I'm no big fan of this kind
of do-what-I-mean API style. I prefer explicitness. If you want to
work on a library that does a lot of helpful things under the covers,
I think that's best tackled as a layer on top of Postmodern, so that
people who want a different approach, or just the basics, don't have
to deal with it.

Best,
Marijn

On Wed, May 9, 2012 at 7:27 PM, Greg Pfeil <greg at technomadic.org> wrote:
> I've made a few changes to Postmodern. They both try to do a little magic in the case where a table has a single primary key column. The first change allows you to use a DAO-OBJECT directly as a parameter, rather than pulling out the key field. EG:
>
>> (select-dao 'foo (:= 'bar bar))
>
> instead of having to do
>
>> (select-dao 'foo (:= 'bar (id bar)))
>
> And the second allows the use of a DAO-CLASS name in the :COL-TYPE field of a slot definition. EG:
>
>> (defclass bar () ((id :col-type serial)) (:metaclass dao-class))
>> (defclass foo () ((bar :col-type (or db-null bar))) (:metaclass dao-class))
>
> instead of
>
>> (defclass bar () ((id :col-type serial)) (:metaclass dao-class))
>
>> (defclass foo () ((bar :col-type (or db-null integer))) (:metaclass dao-class))
>
>
> These both seem pretty basic, but they mean that you can change the primary key column name or type without having to make changes throughout your code. Also, I see it as a first step toward being able to (eagerly or lazily) auto-populate slots with full objects rather than keys.
>
> Does this seem useful, too magical, or already there but I missed it?
>
>
> _______________________________________________
> postmodern-devel mailing list
> postmodern-devel at common-lisp.net
> http://lists.common-lisp.net/cgi-bin/mailman/listinfo/postmodern-devel
>



From achambers at mcna.net  Sat May 12 20:49:18 2012
From: achambers at mcna.net (Andy Chambers)
Date: Sat, 12 May 2012 16:49:18 -0400
Subject: [postmodern-devel] S-SQL extension :if=
Message-ID: <CAAfW55qYLYrR0Co-6O=3WOsxE3og1jdFdRe8LS-M7jPkGjVSMA@mail.gmail.com>

Hi All,

If anyone's interested in using it, I made a little S-SQL extension

(def-sql-op :=if (a b)
  `(,@(case a
        (:null (sql-expand `(:is-null ,b)))
        (nil (sql-expand t))
        (otherwise (sql-expand `(:= ,a ,b))))))

I find it convenient when writing queries that take optional
parameters where if the parameter is not specified, you want to return
the row regardless of what value b takes.  Does anyone else write
little extensions like these?  Should we collect them in a contrib?


-- 
Andy Chambers
Software Engineer
(e) achambers at mcna.net
(t) 954-682-0573

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From marijnh at gmail.com  Mon May 14 19:33:09 2012
From: marijnh at gmail.com (Marijn Haverbeke)
Date: Mon, 14 May 2012 21:33:09 +0200
Subject: [postmodern-devel] S-SQL extension :if=
In-Reply-To: <CAAfW55qYLYrR0Co-6O=3WOsxE3og1jdFdRe8LS-M7jPkGjVSMA@mail.gmail.com>
References: <CAAfW55qYLYrR0Co-6O=3WOsxE3og1jdFdRe8LS-M7jPkGjVSMA@mail.gmail.com>
Message-ID: <CAJnHWXuRn9mixmScDKobynh0twWJ+O=P13VaT+NR9Sb-qz+KSw@mail.gmail.com>

Hi Andy,

If you want, you can create a wiki page on the Postmodern github wiki
[1] for people to collect such snippets. There's not no huge community
around Postmodern, so I'm not sure how much of a market there is for
sharing snipptets, but it can't hurt to preserve them somewhere.

[1]: https://github.com/marijnh/postmodern/wiki

Best,
Marijn