Qt Ada database support?

Qt Ada database support?

[Stephen Leake]

I currently have a small database application, implemented using
GtkAda and GNADE ODBC, using a MySQL backend.

I'd like to switch to a direct connection to an SQLite3 database,
mainly because the administration is much simpler. For example, I
could not get an ODBC connection to a MySQL database installed, let
alone working, on my Debian box (I currently have it working on
Windows XP). The MySQL installation instructions are woefully out of
date.

The GNADE binding to SQLite3 is very minimal. I wouldn't mind very
much improving it, but I'm investigating alternatives first.

Does anyone know of an ODBC connector for SQLite3? Searching on
Ask.com found:

http://www.ch-werner.de/sqliteodbc/, which doesn't look current.

http://www.patthoyts.tk/sqlite3odbc.html, which is Windows only, but
current

I'm also looking at QtAda, and the QtSQL class. The documentation for
QtSQL (http://doc.trolltech.com/4.5/qtsql.html) doesn't say anything
about the database backends; it appears to assume an ODBC connection.

Can anyone confirm that QtSQL uses ODBC? or can it connect directly to
SQLite3?

-- 
-- Stephe

Re: Qt Ada database support?

[Vadim Godunko]

On Jun 9, 3:30 pm, Stephen Leake <stephen_le...@stephe-leake.org>
wrote:
>
> I'm also looking at QtAda, and the QtSQL class. The documentation for
> QtSQL (http://doc.trolltech.com/4.5/qtsql.html) doesn't say anything
> about the database backends; it appears to assume an ODBC connection.
>
> Can anyone confirm that QtSQL uses ODBC? or can it connect directly to
> SQLite3?
>
QtSQL module uses SQLite "as is", without ODBC connection. See

http://doc.trolltech.com/4.5/sql-driver.html

Re: Qt Ada database support?

[Stephen Leake]

Vadim Godunko <vgodunko@gmail.com> writes:

> On Jun 9, 3:30�pm, Stephen Leake <stephen_le...@stephe-leake.org>
> wrote:
>>
>> I'm also looking at QtAda, and the QtSQL class. The documentation for
>> QtSQL (http://doc.trolltech.com/4.5/qtsql.html) doesn't say anything
>> about the database backends; it appears to assume an ODBC connection.
>>
>> Can anyone confirm that QtSQL uses ODBC? or can it connect directly to
>> SQLite3?
>>
> QtSQL module uses SQLite "as is", without ODBC connection. See
>
> http://doc.trolltech.com/4.5/sql-driver.html

Excellent. Thanks.

It would be nice if there was a link to that page from the QtSQL page
...

-- 
-- Stephe

Re: Qt Ada database support?

[Ludovic Brenta]

Stephen Leake wrote on comp.lang.ada:
> I currently have a small database application, implemented using
> GtkAda and GNADE ODBC, using a MySQL backend.
>
> I'd like to switch to a direct connection to an SQLite3 database,
> mainly because the administration is much simpler. For example, I
> could not get an ODBC connection to a MySQL database installed, let
> alone working, on my Debian box (I currently have it working on
> Windows XP). The MySQL installation instructions are woefully out of
> date.
>
> The GNADE binding to SQLite3 is very minimal. I wouldn't mind very
> much improving it, but I'm investigating alternatives first.
>
> Does anyone know of an ODBC connector for SQLite3? Searching on
> Ask.com found:
[...]

SQLite is merely a shared library that you link into your program; it
runs as part of your process. There is no SQLite server and, as far as
I know, no need for an ODBC connection.

GNADE contains two bindings to SQLite: sqlite and sqlite3. The latter
is more complete but even sqlite seems sufficient to me because it
does not have or need the complexity of ODBC. It does lack the concept
of prepared statements, however; this is present in the sqlite3
binding.

Did you have some specific feature in mind?

--
Ludovic Brenta.

Re: Qt Ada database support?

[Stephen Leake]

Ludovic Brenta <ludovic@ludovic-brenta.org> writes:

> Stephen Leake wrote on comp.lang.ada:
>> I currently have a small database application, implemented using
>> GtkAda and GNADE ODBC, using a MySQL backend.
>>
>> I'd like to switch to a direct connection to an SQLite3 database,
>> mainly because the administration is much simpler. For example, I
>> could not get an ODBC connection to a MySQL database installed, let
>> alone working, on my Debian box (I currently have it working on
>> Windows XP). The MySQL installation instructions are woefully out of
>> date.
>>
>> The GNADE binding to SQLite3 is very minimal. I wouldn't mind very
>> much improving it, but I'm investigating alternatives first.
>>
>> Does anyone know of an ODBC connector for SQLite3? Searching on
>> Ask.com found:
> [...]
>
> SQLite is merely a shared library that you link into your program; it
> runs as part of your process. 

Yes.

> There is no SQLite server and, as far as I know, no need for an ODBC
> connection.

If by "connection" we mean "sockets or something similar", then you
are correct. But it would be possible to have an ODBC "wrapper", so
the same ODBC API can be used. That's what I was looking for; that
would be a _much_ smaller change to my code.

Or a more ambitious system could run a process that accessed the
SQLite database, and provided ODBC socket connections. That's _not_
what I'm looking for, of course :).

> GNADE contains two bindings to SQLite: sqlite and sqlite3. The latter
> is more complete but even sqlite seems sufficient to me because it
> does not have or need the complexity of ODBC. It does lack the concept
> of prepared statements, however; this is present in the sqlite3
> binding.
>
> Did you have some specific feature in mind?

Cursors. 

Hmm. Maybe that's what the "Step" function is? I missed that on my
first read thru. I expect to understand things just from reading Ada
specs, but I guess I need to read the SQLite3 docs. Ah, here it is:
http://www.sqlite.org/c3ref/step.html. And yes, that does what ODBC
cursors do; access data tables one row at a time.

That talks about a "new" prepare statement; apparently SQLite is a
moving target. Sigh.

It would be nice if GNADE had a database abstraction layer, so
changing from MySQL to SQLite was more transparent. I think that's
what the "ADO" packages were intended to be, but they are gone now.
QtSQL is such a layer.

I guess if I'm really ambitious I should port/translate QtSQL to a Gtk
class GtkSQL, with GNADE backends. I'll at least think about it. Is
anyone else interested in such a thing? 

Although the first step in such a project would be to actually use
QtSQL, to be sure I really understand it, so I'd be tempted to stop
after that :).

Note that I have a bias towards Gtk over Qt. That's because I have a
history with AdaCore (who maintain Gtk), and none with TrollTech (who
maintain Qt). The Debian project supports both, but there seems to be
a general preference for Gtk; Gnome is the default desktop, for
instance.

-- 
-- Stephe

Qt vs. GTK+ (was: Qt Ada database support?)

[Ludovic Brenta]

Stephen Leake wrote on comp.lang.ada:
> Note that I have a bias towards Gtk over Qt. That's because I have a
> history with AdaCore (who maintain Gtk), and none with TrollTech (who
> maintain Qt). The Debian project supports both, but there seems to be
> a general preference for Gtk; Gnome is the default desktop, for
> instance.

In Debian 5.0 "Lenny", there are different installer CD-ROMs for each
of GNOME, KDE, XFCE and LXDE so the fact that GNOME is the "default"
is somewhat blurred now.

However, it is true that QtAda is not in Debian whereas GtkAda is.
Nobody has yet stepped up to package QtAda for Debian.

The fact that Qt is pure GPL whereas GTK+ is LGPL might be important
to some people but not for Ada programmers since both QtAda and GtkAda
are pure GPL.

--
Ludovic Brenta.

Re: Qt vs. GTK+ (was: Qt Ada database support?)

[Vadim Godunko]

On Jun 10, 2:45 pm, Ludovic Brenta <ludo...@ludovic-brenta.org> wrote:
>
> The fact that Qt is pure GPL whereas GTK+ is LGPL might be important
> to some people but not for Ada programmers since both QtAda and GtkAda
> are pure GPL.
>
Qt Software/Nokia released Qt 4.5 under GPL _and_ LGPL - you can
choose what you want. Nethertheless, it doesn't change anything in Ada
world.

Re: Qt Ada database support?

[Ludovic Brenta]

Stephen Leake wrote on comp.lang.ada:
> It would be nice if GNADE had a database abstraction layer, so
> changing from MySQL to SQLite was more transparent. I think that's
> what the "ADO" packages were intended to be, but they are gone now.
> QtSQL is such a layer.

Perhaps another possibility would be to wrap the GNADE SQLite binding
in an ODBC API; there would be no need for a separate process or
network connection, just a simple translation from the ODBC vocabulary
to the SQLite vocabulary (e.g. "cursors" to "step").

--
Ludovic Brenta.

Re: Qt Ada database support?

[Stephen Leake]

Ludovic Brenta <ludovic@ludovic-brenta.org> writes:

> Stephen Leake wrote on comp.lang.ada:
>> It would be nice if GNADE had a database abstraction layer, so
>> changing from MySQL to SQLite was more transparent. I think that's
>> what the "ADO" packages were intended to be, but they are gone now.
>> QtSQL is such a layer.
>
> Perhaps another possibility would be to wrap the GNADE SQLite binding
> in an ODBC API; there would be no need for a separate process or
> network connection, just a simple translation from the ODBC vocabulary
> to the SQLite vocabulary (e.g. "cursors" to "step").

Yes. That's probably what I'll do, at least for the subset of the ODBC
API that my app currently uses.

Then a smaller part of my app needs to change to use SQLite.

-- 
-- Stephe

Re: Qt Ada database support?

[Maciej Sobczak]

On 9 Cze, 13:30, Stephen Leake <stephen_le...@stephe-leake.org> wrote:

> For example, I
> could not get an ODBC connection to a MySQL database installed, let
> alone working, on my Debian box

You might be more lucky with this:

http://www.inspirel.com/soci-ada

This library uses native client layer for the target database. No
configuration and no messing with ODBC is needed.

--
Maciej Sobczak * www.msobczak.com * www.inspirel.com

Re: Qt Ada database support?

[Stephen Leake]

Maciej Sobczak <see.my.homepage@gmail.com> writes:

> On 9 Cze, 13:30, Stephen Leake <stephen_le...@stephe-leake.org> wrote:
>
>> For example, I
>> could not get an ODBC connection to a MySQL database installed, let
>> alone working, on my Debian box
>
> You might be more lucky with this:
>
> http://www.inspirel.com/soci-ada

This is interesting. But it's based on a C++ library; I really don't
want more non-Ada code between me and my data.

> This library uses native client layer for the target database. No
> configuration and no messing with ODBC is needed.

That would be nice. But I suspect all I really need for MySQL on
Debian is a current HOWTO. Somebody must have one! Maybe I just need
to look harder ...

-- 
-- Stephe

Re: Qt Ada database support?

[Maciej Sobczak]

On 10 Cze, 12:45, Stephen Leake <stephen_le...@stephe-leake.org>
wrote:

> > You might be more lucky with this:
>
> >http://www.inspirel.com/soci-ada
>
> This is interesting. But it's based on a C++ library; I really don't
> want more non-Ada code between me and my data.

I have a bad news for you. The operating system, the database server
and its native client library (including all possible layers for ODBC
drivers) are non-Ada...

Actually, the SOCI library omits the ODBC drivers, which are
themselves non-trivial, on both server and client side. I never
counted the volume, but I would not be surprised to see that SOCI
implies much less of that non-Ada ugly thingy than ODBC, so you might
be as well completely wrong with your judgements.

Just think of it - you want to avoid non-Ada code you you get more of
it. :-)

--
Maciej Sobczak * www.msobczak.com * www.inspirel.com

Database Access Library for Ada: www.inspirel.com/soci-ada

Re: Qt Ada database support?

[Stephen Leake]

Maciej Sobczak <see.my.homepage@gmail.com> writes:

> On 10 Cze, 12:45, Stephen Leake <stephen_le...@stephe-leake.org>
> wrote:
>
>> > You might be more lucky with this:
>>
>> >http://www.inspirel.com/soci-ada
>>
>> This is interesting. But it's based on a C++ library; I really don't
>> want more non-Ada code between me and my data.
>
> I have a bad news for you. The operating system, the database server
> and its native client library (including all possible layers for ODBC
> drivers) are non-Ada...

I know that. I said "more", not "any" :).

> Actually, the SOCI library omits the ODBC drivers, which are
> themselves non-trivial, on both server and client side. I never
> counted the volume, but I would not be surprised to see that SOCI
> implies much less of that non-Ada ugly thingy than ODBC, so you might
> be as well completely wrong with your judgements.

Good point. However, that is part of why I'm switching to SQLite;
those ODBC drivers require installation and administration, and I
can't figure out how to do that on Debian. I can figure out how to
install SQLite on Debian.

-- 
-- Stephe

Re: Qt Ada database support?

[Ludovic Brenta]

Stephen Leake wrote on comp.lang.ada:
> those ODBC drivers require installation and administration, and I
> can't figure out how to do that on Debian. I can figure out how to
> install SQLite on Debian.

How about http://www.debian-administration.org/articles/496 ? Does it
help? It may be outdated though.

--
Ludovic Brenta.

Re: Qt Ada database support?

[Stephen Leake]

Ludovic Brenta <ludovic@ludovic-brenta.org> writes:

> Stephen Leake wrote on comp.lang.ada:
>> those ODBC drivers require installation and administration, and I
>> can't figure out how to do that on Debian. I can figure out how to
>> install SQLite on Debian.
>
> How about http://www.debian-administration.org/articles/496 ? Does it
> help? It may be outdated though.

That looks helpful. In particular, it says the unixODBC package
includes the MySQL drivers. Which means (I think), I don't need the
MySQL connector, which is what I couldn't find on the MySQL website!

And it has instructions for all the other steps, too.

I'm sure I can adapt to version number changes.

Thanks for the link; that website looks good in general.

-- 
-- Stephe

Re: Qt Ada database support?

[Ludovic Brenta]

Stephen Leake wrote on comp.lang.ada:
> Ludovic Brenta <ludo...@ludovic-brenta.org> writes:
> > Stephen Leake wrote on comp.lang.ada:
> >> those ODBC drivers require installation and administration, and I
> >> can't figure out how to do that on Debian. I can figure out how to
> >> install SQLite on Debian.
>
> > How abouthttp://www.debian-administration.org/articles/496? Does it
> > help? It may be outdated though.
>
> That looks helpful. In particular, it says the unixODBC package
> includes the MySQL drivers. Which means (I think), I don't need the
> MySQL connector, which is what I couldn't find on the MySQL website!
>
> And it has instructions for all the other steps, too.
>
> I'm sure I can adapt to version number changes.
>
> Thanks for the link; that website looks good in general.

No, AFAIU, unixodbc does not include the MySQL connector; you have to
install the complementary package "libmyodbc" to get that. While
researching this I noticed there also exists a package
"libsqliteodbc" :) Debian keeps surprising me in good ways :)

--
Ludovic Brenta.

Re: Qt Ada database support?

[Emmanuel Briot]

The GNAT Components Collection (gnatcoll) was released some time ago
and is part of the public release. Among a lot of other goodies, it
includes the GNATCOLL.SQL hierarchy of packages, which abstract the
DBMS backend, while providing additional features, like Ada
subprograms to write syntactically correct queries, local caches of
query results, type safety,...
We had published a paper at Ada Europe 2008 about it.

The last release only includes support for postgresSQL, but we
recently added support for sqlite3 (which by the way required a major
redesign of the API). Adding mysql is part of the plan and should be
rather easy now.

You could look into that (either by accessing the public subversion
repositories, or through your usual support contract)

Emmanuel

Status of GNADE (Was: Qt Ada database support?)

[Tomek Wałkuski]

Really fast question: what is the status of GNADE? Is it still
maintained?

Re: Status of GNADE

[Stephen Leake]

Tomek Wałkuski <tomek.walkuski@gmail.com> writes:

> Really fast question: what is the status of GNADE? Is it still
> maintained?

It's easy to ask a question "fast", but not so easy to answer it.

I'm listed as a developer on the SourceForge GNADE website
http://gnade.sourceforge.net/, but I haven't done any work on it for 5
years. 

Other people have done some work.

I'm getting back into it now.

If you look at the CVS history, you'll see some recent changes.

I'm always a little puzzled by questions like this. If GNADE is
currently useful for you, then you should use it. If it has problems
that you need fixed, ask about them here. If no-one responds, and you
can't fix it yourself, then you can conclude that GNADE is not
maintained.

I guess it would be nice to have some notion of whether someone
_would_ respond, so you can decide whether to invest time in GNADE or
QtSQL or GNATCOLL.SQL. Then you just have to go by the reputation of
the maintaining organization. SourceForge groups in general will be
less reliable than successful companies, but there are always
exceptions (the all-volunteer monotone support group is _way_ better
than a certain commerical OS company I am forced to deal with).

So I'm suggesting that a more useful question would be "has anyone had
any recent experience with getting help with GNADE". That would give
you better information about the current state of the project.

-- 
-- Stephe

Re: Qt Ada database support?

[Stephen Leake]

Emmanuel Briot <briot.emmanuel@gmail.com> writes:

> The GNAT Components Collection (gnatcoll) was released some time ago
> and is part of the public release. Among a lot of other goodies, it
> includes the GNATCOLL.SQL hierarchy of packages, which abstract the
> DBMS backend, while providing additional features, like Ada
> subprograms to write syntactically correct queries, local caches of
> query results, type safety,...
> We had published a paper at Ada Europe 2008 about it.

There is interesting stuff in that collection.

I guess I should read the proceedings of the Ada Europe conferences;
looks like they'll be available on-line in a few months
http://www.ada-europe.org/AUJ/index.html 

> The last release only includes support for postgresSQL, but we
> recently added support for sqlite3 (which by the way required a major
> redesign of the API). 

It is difficult to design a "generic multi-backend API" when you only
have one backend!

> Adding mysql is part of the plan and should be rather easy now.
>
> You could look into that (either by accessing the public subversion
> repositories, or through your usual support contract)

This is for home stuff, so I don't want to do it thru my support
contract. I'll see if I can access the public repository; that will be
my first use of subversion (I went straight from CVS to monotone :).

-- 
-- Stephe

Re: Qt Ada database support?

[Ludovic Brenta]

On Jun 12, 12:54 pm, Stephen Leake <stephen_le...@stephe-leake.org>
wrote:
> Emmanuel Briot <briot.emman...@gmail.com> writes:
> > The GNAT Components Collection (gnatcoll) was released some time ago
> > and is part of the public release. Among a lot of other goodies, it
> > includes the GNATCOLL.SQL hierarchy of packages, which abstract the
> > DBMS backend, while providing additional features, like Ada
> > subprograms to write syntactically correct queries, local caches of
> > query results, type safety,...
> > We had published a paper at Ada Europe 2008 about it.
>
> There is interesting stuff in that collection.
>
> I guess I should read the proceedings of the Ada Europe conferences;
> looks like they'll be available on-line in a few monthshttp://www.ada-europe.org/AUJ/index.html
>
> > The last release only includes support for postgresSQL, but we
> > recently added support for sqlite3 (which by the way required a major
> > redesign of the API).
>
> It is difficult to design a "generic multi-backend API" when you only
> have one backend!
>
> > Adding mysql is part of the plan and should be rather easy now.
>
> > You could look into that (either by accessing the public subversion
> > repositories, or through your usual support contract)
>
> This is for home stuff, so I don't want to do it thru my support
> contract. I'll see if I can access the public repository; that will be
> my first use of subversion (I went straight from CVS to monotone :).

You can keep using monotone if you want.  I mirror AdaCore's
repository into Ada-France's monotone database. Gnatcoll is currently
part of GPS (branch com.adacore.gps) in subdirectory gnatlib/src.

When I get around to upgrading GPS in Debian, I'll see if I can
produce separate binary packages of gnatcoll (i.e. libgnatcoll-dev,
libgnatcoll0, libgnatcoll-dbg and perhaps libgnatcoll-doc) from the
sources. Anyone willing to help?

--
Ludovic Brenta.

GNADE, ODBC and MySQL

[Björn Persson]

Stephen Leake wrote:

> I currently have a small database application, implemented using
> GtkAda and GNADE ODBC, using a MySQL backend.
> 
> I'd like to switch to a direct connection to an SQLite3 database,
> mainly because the administration is much simpler. For example, I
> could not get an ODBC connection to a MySQL database installed, let
> alone working, on my Debian box (I currently have it working on
> Windows XP). The MySQL installation instructions are woefully out of
> date.

My spam blocker uses MySQL through GNADE and ODBC on Debian Etch, and it's
working great. It took some experimentation before I understood how to
configure ODBC, but it didn't seem all that difficult to me.

I'm not exactly a guru on these things but if you want to troubleshoot my
first question will be what ODBC related packages you have installed, and
whether you installed them from Debian's repositories of some other way.

-- 
Bj�rn Persson
PGP key A88682FD