Dolphin and Paradox tables

Hi there,

I'll have to do some maintenance on some Delphi app extracting
information from Paradox tables and I don't want to relearn all
of that static typing stuff and what not ...

So, what would be the best way to access (heh!) Paradox tables
from a (headless, Customer only wants lots of command line switches :-)
Dolphin application?

What would I have to do to deal with the BDE?
Does ODBC work on recent Paradox tables?
Maybe ReStore? (hey, I even got a license for this :-)

Thanks,
s.

Stefan Schmiedl <[hidden email]> wrote in news:b64fs7$1l25c$1@ID-
57631.news.dfncis.de:

Hi Stefan,

First of all - I've know idea if you can access Paradox table from Dolphin,
I suspect that you can't. I'm responding because I'm trying to disuade you
from using Paradox tables. Of all the desktop databases (dBase, Paradox and
Access), Paradox suffers the most from index corruptions under Windows in a
multi-user environment (Access is the least worst I believe). This
corruption manifests itself as "Index Out of Date" errors and will require
you to rebuild the offending index(es) whenever this occurs. You will have
to rebuild the indexes in single user mode too because you'll need
exclusive access to the data. Also, Paradox tends to grind to a halt at
about 15 users if they are doing intensive updates, apps that predominately
read data will get away with more connected users before problems arise.

If you must use Paradox then I recommend access to your data through the
BDE (btw, this is now a deprecated product) and to use that effectively
then you will need to use either Delphi or C++Builder which have a lot of
support for the BDE.

Through bitter experience I strongly recommend that you use anything other
than Paradox to hold your data what ever language you use. If you have to
use a desktop database technology then I would recommned that you use
Access as the engine (MDAC) is easily and freely available and I'm sure
that Dolphin supports ADO/OLE DB, perhaps someone with more Dolphin
database experience could confirm this.

Hope this helps

Regards

Barry Carr
Ixian Software Components Ltd
Blairgowrie
Scotland

"Stefan Schmiedl" <[hidden email]> wrote in message
news:b64fs7$1l25c$[hidden email]...
Try a Google search, it looks like there are ODBC drivers for Paradox (
http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=Paradox+ODBC ).  If
so you could use the DBConnection in Dolphin, see the old Education Center
(
http://www.object-arts.com/Lib/EducationCentre4/htm/databaseconnectivity.htm
 ) for more info, or the ADO wrapper in Dolphin, see the MS documentation
( http://www.microsoft.com/data/ado/default.htm ) for more info.  If you are
interfacing with an existing database structure I do not think ReStore will
be the right tool to use, without customization.  The standard version of
ReStore needs to dictate the structure of the database.  That is great when
you create the database, but will not make it easy to work with an existing
database.

Chris

On Mon, 31 Mar 2003 18:42:59 +0000 (UTC),
Barry Carr <[hidden email]> wrote:
>
> I suspect that you can't. I'm responding because I'm trying to disuade you
> from using Paradox tables.

Hi Barry,

thanks for your reply. Unfortunately, I have no choice, as the
application creating the tables is not mine. I only have written an
add-on product for building web pages out of the information.

> Of all the desktop databases (dBase, Paradox and
> Access), Paradox suffers the most from index corruptions under Windows in a
> multi-user environment (Access is the least worst I believe).

There have been some issues re: Optimistic Locking we had to tweak in
the registry, but I have heard no complaints, after the system was
correctly set up.

> This
> corruption manifests itself as "Index Out of Date" errors and will require
> you to rebuild the offending index(es) whenever this occurs. You will have
> to rebuild the indexes in single user mode too because you'll need
> exclusive access to the data. Also, Paradox tends to grind to a halt at
> about 15 users if they are doing intensive updates, apps that predominately
> read data will get away with more connected users before problems arise.

All desktop databases do this ... at least I know none, which does not.

>
> Through bitter experience I strongly recommend that you use anything other
> than Paradox to hold your data what ever language you use. If you have to
> use a desktop database technology then I would recommned that you use
> Access as the engine (MDAC) is easily and freely available and I'm sure
> that Dolphin supports ADO/OLE DB, perhaps someone with more Dolphin
> database experience could confirm this.
>

I had some experiences with Access databases which were similar to your
Paradox encounters ... crashes destroying all of the tables stored
"behind" the corrupt one, stuff like that.

The main problem I have nowadays with Paradox is that you basically have
only one way to access the data, as you said.

We'll see, what comes out of this.

s.

Hi Christopher,

On Mon, 31 Mar 2003 16:41:38 -0500,
Christopher J. Demers <[hidden email]> wrote:
> Try a Google search, it looks like there are ODBC drivers for Paradox (
> http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=Paradox+ODBC ).

I've tried lots of combinations with "dolphin" and ("odbc" or "paradox")
but did not try "odbc" and "paradox" ... might be that I'm getting too
old for this stuff :-)


> If
> so you could use the DBConnection in Dolphin, see the old Education Center
> (
> http://www.object-arts.com/Lib/EducationCentre4/htm/databaseconnectivity.htm
>  ) for more info, or the ADO wrapper in Dolphin, see the MS documentation
> ( http://www.microsoft.com/data/ado/default.htm ) for more info.

Thanks alot for the pointers, they're very helpful.

s.

A little off topic, but I recently had to read dBase files from a legacy
app and took the direct approach of using an all smalltalk approach (no
odbc, dao etc ..) (This work was performed in VisualWorks)

I used a VW port of
ftp://st.cs.uiuc.edu/pub/Smalltalk/Squeak/goodies/XBaseFile.st to directly
read and write to the dbase files.
 A quick look at the paradox file specs :
http://www.byronref.com/rmb/pxspecs.htm , and you should be able to read
the files with a couple of days work.

Just my two cents ...

Edward Stow

On 29 Mar 2003 15:59:03 GMT, Stefan Schmiedl <[hidden email]> wrote:



--
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/

On Mon, 31 Mar 2003 23:42:17 GMT,
Edward Stow <[hidden email]> wrote:
> A little off topic, but I recently had to read dBase files from a legacy
> app and took the direct approach of using an all smalltalk approach (no
> odbc, dao etc ..) (This work was performed in VisualWorks)

cool ...

>
> I used a VW port of
> ftp://st.cs.uiuc.edu/pub/Smalltalk/Squeak/goodies/XBaseFile.st to directly
> read and write to the dbase files.
>  A quick look at the paradox file specs :
> http://www.byronref.com/rmb/pxspecs.htm , and you should be able to read
> the files with a couple of days work.

neat. I'll take a look at this, too.

thanks, Edward.

s.