Re: DBMS that integrates well with object-oriented programming
BH> After converting the data in my project from text files to MySQL BH> tables, things are certainly working more smoothly than they were BH> before, but since I use objects (in Perl, which barely supports BH> objects, but that's another story) I have to write a lot of annoyingly BH> repetitive code to create the object, run a query on the database to BH> get the data that I need, set the object's member variables equal to BH> the results returned from the query, and then do all those steps in BH> reverse if the object's member values have changed later. There is a number of CPAN modules which provide OO access for SQL database. Take a look at http://poop.sourceforge.net. -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | Ilya Martynov (http://martynov.org/)| | GnuPG 1024D/323BDEE6 D7F7 561E 4C1D 8A15 8E80 E4AE BE1A 53EB 323B DEE6 | | AGAVA Software Company (http://www.agava.com/) | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: DBMS that integrates well with object-oriented programming
On Thu, Nov 15, 2001 at 03:18:58AM -0800, Bennett Haselton wrote:
> >
> >Hmm... I'm sure plenty of people would disagree strongly with your
> >remark of bad OO support in Perl. But, that is beside the
> >point. You could either search CPAN (http://www.cpan.org/) and see
> >if you find what you need there (Surely somebody had the same
> >problem already), and if not, take a look at the AUTOLOAD "magic"
> >sub in Perl (that'd be perldoc perlsub, search for 'Autoloading').
>
> I can't do it in Perl.
What's "it"?
> I can't even quantify the amount of money we've already lost by
> using Perl.
Funny, I can't imagine to begin to quantify the amount of time (or
money) we've saved by using Perl!
But this isn't a language war (yet?).
> By not supporting OO, I mean things like the fact that if you define
> a member function of a class, then
>
> $classname::functionname($arg1, $arg2);
> and
> $classname->functionname($arg1, $arg2);
>
> will both compile, but one is a static function that passes the
> class name as the first argument, and the other is a non-static
> function that passes the arguments as listed.
What's the prototype on functionname() look like? Using a prototype
of ($$$) would have made that a compile-time error, so don't blame
Perl!
> No one on any Perl list that I'm on could make sense of why they did
> that.
Why who did what?
> If you wanted a static function, you'd make it static; otherwise,
> you'd make it non-static.
How, exactly?
> The way Perl does it, you have to put some logic at the beginning of
> your function to check whether the first argument is the class name,
> and if it is, branch into the "static" function code, or else branch
> to the "non-static" function code.
Well, most folks write methods and only write them to be called as
methods. If their first argument isn't an object ref, they should
bail.
Mixing "static" and "dynamic" stuff in a single function doesn't sound
like a good idea to me (unless you're talking about new(), which is
typically a constructor).
> Bizarre. I think that to the maximum extent possible, a programming
> language should ensure that a typo will cause the program *not to
> run*, instead of running and doing something unexpected.
Oh, you just want a strictly typed language. Then Perl is certainly
not for you. Maybe C++ is more up your alley.
> Has anyone used a beta of Visual Studio .NET enough to know if it can do
> all of this? i.e. being able to do something along the lines of
Which language? .NET is not a language. It's a framework.
> user myuser = user.GetObjectFromTableRow("bennett");
> myuser.sendReminders();
> myuser.emailaddress = '[EMAIL PROTECTED]';
>
> in three lines -- with Perl and MySQL it takes about 20.
Assuming that someone has already built a good "user" class, you can
also do it in three lines of Perl. Or Python. Or VisualBasic. Or
whatever. I think that then language really isn't the issue in this
case.
> I think there are some purposes that free, open-source software is
> better suited for (security protocols and other well-defined
> problems that don't change with a constantly changing technological
> environment), however the question of when and when not to use open
> source software is clouded by the notion that open-source software
> is always better. If I'm going to be using an IDE to do rapid
> application development, I want a **closed-source**, **proprietary**
> system that **costs money** :)
And you're free to choose whatever you'd like. I've used both and
have had success with both.
Jeremy
--
Jeremy D. Zawodny, <[EMAIL PROTECTED]>
Technical Yahoo - Yahoo Finance
Desk: (408) 349-7878 Fax: (408) 349-5454 Cell: (408) 685-5936
MySQL 3.23.41-max: up 71 days, processed 1,555,847,080 queries (253/sec. avg)
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Re: DBMS that integrates well with object-oriented programming
On Thu, Nov 15, 2001 at 01:49:31AM -0800, Bennett Haselton wrote:
>
> After converting the data in my project from text files to MySQL
> tables, things are certainly working more smoothly than they were
> before,
Good to hear.
> but since I use objects (in Perl, which barely supports objects, but
> that's another story)
What does that mean, exactly? I do a lot of OO in Perl.
> I have to write a lot of annoyingly repetitive code to create the
> object, run a query on the database to get the data that I need, set
> the object's member variables equal to the results returned from the
> query, and then do all those steps in reverse if the object's member
> values have changed later.
Well, it *is* Perl. If you find yourself doing something repetitive,
the little programmer in your head should wake up and think "how can I
write a program to do all this repetitive work so that I can sit on a
tropical beach?" :-)
> Are there any database systems that integrate so smoothly with an
> object-oriented programming language that I would be able to write
> code like:
>
> my $user = user.CreateFromTableRow("bennett");
> $user.sendReminderEmails();
> $user.emailaddress = '[EMAIL PROTECTED]';
>
> and the appropriate values would get read and written to the
> underlying database table. There's no reason why a language/IDE
> designed to integrate databases and objects would require more than
> three lines of code for that.
I was in a discussion about this a week or so ago with a co-worker.
We could decide if it ought to be Ruby, Python, or C++. But we had
some interesting ideas that would be fun to try and implement someday.
I don't know of one yet, but I've heard good things about Zope's
object database (ZODB?)
> An ideal database and language integration system could have the following
> features:
> (a) there is an automatic one-to-one correspondence between fields in a
> database table and member variables of the object
In Perl, you can used a tied hash to do that already.
> (b) any field that is a unique key
What's that mean?
> (c) modifications of the object member variable values get written through
> directly to the database
Tied hashes do that, too.
> (d) queries can be done in-place, in code, with a function that takes a
> reference to another function and returns all elements in the table for
> which that function returns true, i.e. this example in pseudocode would
> return an array of all objects corresponding to rows in the table
> "automobile" where the price is less than 1:
> my @user_array = GetMatches('automobile_table',
> function myfunc($automobile)
> {
> if ($automobile.price < 1)
> {
> return true;
> }
> }
> );
That doesn't look to hard to do, either. Have you looked at all the
database related modules on the CPAN?
Jeremy
--
Jeremy D. Zawodny, <[EMAIL PROTECTED]>
Technical Yahoo - Yahoo Finance
Desk: (408) 349-7878 Fax: (408) 349-5454 Cell: (408) 685-5936
MySQL 3.23.41-max: up 71 days, processed 1,555,776,471 queries (253/sec. avg)
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Re: DBMS that integrates well with object-oriented programming
On Thu, Nov 15, 2001 at 01:49:31AM -0800, Bennett Haselton wrote:
> my $user = user.CreateFromTableRow("bennett");
> $user.sendReminderEmails();
> $user.emailaddress = '[EMAIL PROTECTED]';
You would lose some indexing features, etc., but you could easily use a
language like Python that allows for object serialization and simply
store the serialized objects in the database (look up 'pickle' on
python.org). This is also true with PHP.
1) Create object (class)
2) Use object
3) Serialize & store object
later ...
4) Fetch & deserialize object
5) Use object
6) Re-serialize and store object
--
Michael T. Babcock
CTO, FibreSpeed Ltd.
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Re: DBMS that integrates well with object-oriented programming
At 10:37 AM 11/15/2001 +, [EMAIL PROTECTED] wrote:
>Dear Bennett,
>
>On Thu, 15 Nov 2001, Bennett Haselton wrote:
> > After converting the data in my project from text files to MySQL
> tables,
> > things are certainly working more smoothly than they were before, but
> since
> > I use objects (in Perl, which barely supports objects, but that's
> another
> > story) I have to write a lot of annoyingly repetitive code to create
> the
> > object, run a query on the database to get the data that I need, set
> the
> > object's member variables equal to the results returned from the query,
> and
> > then do all those steps in reverse if the object's member values have
> > changed later.
>
>Hmm... I'm sure plenty of people would disagree strongly with your remark
>of bad OO support in Perl. But, that is beside the point. You could either
>search CPAN (http://www.cpan.org/) and see if you find what you need there
>(Surely somebody had the same problem already), and if not, take a look at
>the AUTOLOAD "magic" sub in Perl (that'd be perldoc perlsub, search for
>'Autoloading').
I can't do it in Perl. I can't even quantify the amount of money we've
already lost by using Perl. By not supporting OO, I mean things like the
fact that if you define a member function of a class, then
$classname::functionname($arg1, $arg2);
and
$classname->functionname($arg1, $arg2);
will both compile, but one is a static function that passes the class name
as the first argument, and the other is a non-static function that passes
the arguments as listed. No one on any Perl list that I'm on could make
sense of why they did that. If you wanted a static function, you'd make it
static; otherwise, you'd make it non-static. The way Perl does it, you
have to put some logic at the beginning of your function to check whether
the first argument is the class name, and if it is, branch into the
"static" function code, or else branch to the "non-static" function
code. Bizarre. I think that to the maximum extent possible, a programming
language should ensure that a typo will cause the program *not to run*,
instead of running and doing something unexpected.
Has anyone used a beta of Visual Studio .NET enough to know if it can do
all of this? i.e. being able to do something along the lines of
user myuser = user.GetObjectFromTableRow("bennett");
myuser.sendReminders();
myuser.emailaddress = '[EMAIL PROTECTED]';
in three lines -- with Perl and MySQL it takes about 20.
I think there are some purposes that free, open-source software is better
suited for (security protocols and other well-defined problems that don't
change with a constantly changing technological environment), however the
question of when and when not to use open source software is clouded by the
notion that open-source software is always better. If I'm going to be
using an IDE to do rapid application development, I want a
**closed-source**, **proprietary** system that **costs money** :)
-Bennett
[EMAIL PROTECTED] http://www.peacefire.org
(425) 649 9024
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Re: DBMS that integrates well with object-oriented programming
Dear Bennett, On Thu, 15 Nov 2001, Bennett Haselton wrote: > After converting the data in my project from text files to MySQL tables, > things are certainly working more smoothly than they were before, but since > I use objects (in Perl, which barely supports objects, but that's another > story) I have to write a lot of annoyingly repetitive code to create the > object, run a query on the database to get the data that I need, set the > object's member variables equal to the results returned from the query, and > then do all those steps in reverse if the object's member values have > changed later. Hmm... I'm sure plenty of people would disagree strongly with your remark of bad OO support in Perl. But, that is beside the point. You could either search CPAN (http://www.cpan.org/) and see if you find what you need there (Surely somebody had the same problem already), and if not, take a look at the AUTOLOAD "magic" sub in Perl (that'd be perldoc perlsub, search for 'Autoloading'). Hope this helps. Sincerely, Jan -- Mr. Jan-Aage Bruvoll IT Project Manager 20 Min Holding, Thurgauerstrasse 40, CH-8050 Zurich Zurich office: +41 1 307 4293, fax: +41 1 307 4281 Office/fax: +44 2072408283 Mobile: +44 7740291600 - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
DBMS that integrates well with object-oriented programming
After converting the data in my project from text files to MySQL tables,
things are certainly working more smoothly than they were before, but since
I use objects (in Perl, which barely supports objects, but that's another
story) I have to write a lot of annoyingly repetitive code to create the
object, run a query on the database to get the data that I need, set the
object's member variables equal to the results returned from the query, and
then do all those steps in reverse if the object's member values have
changed later.
Are there any database systems that integrate so smoothly with an
object-oriented programming language that I would be able to write code
like:
my $user = user.CreateFromTableRow("bennett");
$user.sendReminderEmails();
$user.emailaddress = '[EMAIL PROTECTED]';
and the appropriate values would get read and written to the underlying
database table. There's no reason why a language/IDE designed to integrate
databases and objects would require more than three lines of code for that.
An ideal database and language integration system could have the following
features:
(a) there is an automatic one-to-one correspondence between fields in a
database table and member variables of the object
(b) any field that is a unique key
(c) modifications of the object member variable values get written through
directly to the database
(d) queries can be done in-place, in code, with a function that takes a
reference to another function and returns all elements in the table for
which that function returns true, i.e. this example in pseudocode would
return an array of all objects corresponding to rows in the table
"automobile" where the price is less than 1:
my @user_array = GetMatches('automobile_table',
function myfunc($automobile)
{
if ($automobile.price < 1)
{
return true;
}
}
);
*Sigh* I can dream, I guess. What's actually available? :) (I am *not*
averse to using commercial software products which save more money in the
long run than they cost; please don't *not* tell me about something just
because it's closed source, proprietary, comes from the Evil Empire in
Redmond, etc. :))
-Bennett
[EMAIL PROTECTED] http://www.peacefire.org
(425) 649 9024
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