Board index » jbuilder » JDBC and BDE

2005-01-15 02:01:06 AM
jbuilder24
Hello,
A wierd problem but here goes. Is there any way to use BDE with JDBC ?
The only way possible I could think of was
JDBC->ODBC->BDE . Certainly not the best of ways to work but nothing much
you can do when the so called "managers" decide to promise something not
practical.
Help will be appriciated.
Regards.
 

Ouch!!!
Please, please tell me that your manager hasn't promised that to a client...
Anyway, the short answer is no. Since JDBC was designed to go directly to
the database, I can't imagine anyone in Borland (or anywhere else for that
matter) thinking that the mapping from one abstract access layer to another
would be worthwhile. I'm not even sure what the current status of BDE is
anymore as I'm out of the loop on the Windows family of products.
--
Kevin Dean [TeamB]
Check out our latest white papers at
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"Knopfler" < XXXX@XXXXX.COM >wrote in message

Unfortunatly it has been told to the client. I can only see one work around
that. I guess that would be finding a correct dBase JDBC driver that
respects BDE indexes. I call them BDE indexes since upon close inspection
those MDX index are no where near the format defined for xBase apps.
Few drivers that I have used were not doing that so as for now I am stuck.
It does not matter what sort of business layer you are using, be it
Hibernate, DataExpress or EJBs unless and untill there is a suitable driver
available that can work on the data used in parallel with BDE/Delphi based
apps its a problem.
I will be glad if someone guide me through this or more importantly make me
believe that there is light at the end of the tunnel.
Rgds.
"Kevin Dean [TeamB]" < XXXX@XXXXX.COM >wrote in message

{smallsort}

Knopfler wrote:
are we talking about here?
--
Regards,
Lori Olson [TeamB]
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Well, you have my sympathy. I've also been victim of the over-enthusiastic
sales pitch ("Yes, of course we can do it! And for almost nothing! And by
tomorrow!").
Are there any alternatives that you can consider? Is this a reporting tool
and if so, will a data export do? Are you mimicking transactions in the
Delphi application? If so, what about exposing some of the Delphi
functionality as a web service instead?
I'm surprised to see you saying that the MDX files are not compatible; AFAIK
they should be. What about changing the Delphi application to use BDE->ODBC
and then using JDBC->ODBC so that both BDE and JDBC are going through a
common interface?
--
Kevin Dean [TeamB]
Check out our latest white papers at
www.datadevelopment.com/papers/index.html
BladeNET Scores With Borland Enterprise Tools
Team Development with JBuilder and Borland Enterprise Server
Dolphin Data Development Ltd.
www.datadevelopment.com/
"Knopfler" < XXXX@XXXXX.COM >wrote in message

Thank you guys for your responses.
Kevin: I really wish it was a reporting tool but its not. Its an application
written in Delphi and dBase 4 with BDE being the database engine. All of
the suggestions that you came up with were great but with one problem. Due
to the security/clearence/who knows what standards of US Gov I dont have any
piece of code available. The idea of this project is to convert the existing
app into java,j2ee and all those nice words that non-computer people love to
use. There is zero documentation available for us to see. All we have is a
running app and the RFP which contains a waterfall approach towards non-OOAD
done in 1989 or 90.
Pretty lose lose situation. In other words. "Sorry son you cannot have the
code to our existing app"
Waiting for your reply.
Lori:
Its dBase IV. I know BDE is not a database :). I dont really know if i would
call dBase a Database. Help will be appriciated.
World would be such a better place IF technocrats were part of the board of
directors, executive decision team etc..
"Lori M Olson [TeamB]" < XXXX@XXXXX.COM >wrote in message

And of course the RFP from 1989/1990 probably doesn't reflect the
compromises made during the initial development or any upgrades made since
that time. I'm assuming that this is a phased implementation so you can't
just stop using the old system and start using the new.
Quite frankly, yours is a project I wouldn't touch with a ten foot pole.
The idea of taking an application developed when Windows 3.X was king,
rewriting it in the most modern environment available, and doing it in such
a way that the two can cooperatively access the same database would send me
running for the hills. I would honestly give your project zero chance of
success given those parameters.
Another thing that might kill this project (it pretty much destroyed a
project that I was called in to replace) is that the dBase locking mechanism
varies from vendor to vendor. The system I was replacing had some batch
processing code written using the CodeBase library and a user interface
written in dBase. The indexes were compatible but the locking mechanisms
were not, which means that there was absolutely nothing to prevent the batch
application and the user interface application from updating the same record
at the same time or, worse, updating the indexes at the same time, which
sent the whole thing squirrelly several times a day. The upshot of this is
that even if you find a Java library that seems to cooperate with BDE
there's absolutely no guarantee that it will do so under anything
approaching a heavy load.
Feel free to quote me on the above if it helps you with your boss.
--
Kevin Dean [TeamB]
Dolphin Data Development Ltd.
www.datadevelopment.com/
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"Knopfler" < XXXX@XXXXX.COM >wrote in message

Kevin:
I went into my director's office stating the technical problems
that are and will remain with this project and came out with a
blame of being too negative i.e. in my opinion a little practical. But thats off the topic for now.
Yes this is a phased implementation. I will state how it works just to give you all an over view. In simple this system forms a parent node to 3 other software systems ran by 3 different govt departments. Why are we not converting the leaf nodes first is purely related to how customer wants to go and our marketing team's lack of homework.
I agree with you over the risk assessment part. To be honest, I when first looked at it felt the same way. The only thing thats making me cling on to something is the fact that IF IT CAN WORK WITH SOMETHING THAT WAS WRITTEN LONG TIME AGO I SEE NO REASON WHY IT CANNOT WORK WITH SOMETHING NEW.
Lock issues are very important and can be looked at in a sequential fashion. Once we have a solution to update 2 different rows using old app and the new app in a same table. I am sure there will be a work around locks.
Right now I am looking for ideas, any idea or theory or perhaps an assumption.
Paul: As I stated its a phased implementation. Converting to something of the 21st century is rather not possible.
My apologies fellows, if I in any way am going off from Borland's DataExpress component/framework topic. I just thought this would be a good place to gather some information. Further a good read for the new developers and project managers.
Ideas and thoughts are welcome.
Regards.
"Kevin Dean [TeamB]" < XXXX@XXXXX.COM >wrote:

and that is economics. The number of developers who would conceivably
require a connection from a Java application to a proprietary Windows-based
API like the BDE is so ridiculously small as to be completely ignored; the
cost of developing such compatibility would far and away exceed the revenue
to be achieved from doing it. It's like saying you're going to develop a
new car but that you want it to be compatible with the engine from a Model T
just in case some customer has one lying around that they'd like to use.
Locking is not a trivial exercise, and if you don't have the source code for
the existing application, you have almost no hope of developing a compatible
locking mechanism in the Java side. Even if you had the source code for the
existing application, you probably wouldn't find any explicit locking code
therein as its all handled at the BDE level, and the source code for the BDE
is not available.
In my opinion, your project has failed before it has even begun and the
attitude of your director and the marketing team means that the blame will
be laid squarely at your feet. Good luck.
--
Kevin Dean [TeamB]
Dolphin Data Development Ltd.
www.datadevelopment.com/
Please see Borland's newsgroup guidelines at
info.borland.com/newsgroups/guide.html
"Knopfler" < XXXX@XXXXX.COM >wrote in message

"Knopfler" < XXXX@XXXXX.COM >wrote in message
BDE. I used the BDE up to 5.1, and never saw this. It sounds like they could
be using something like Clipper, instead of straight dBase.
Help me understand something here. If they want a J2EE application, why not
migrate the data to a 21st century database?
That could be done via a Delphi or C++ util that uses the Databases via the
BDE (unless like Kevin states, they are using some unknown third party
drivers). Why anyone would want to use an early model 20th century database
:( with a 21st century application, is beyond me.
As Kevin stated, you can quote me on this. This is not a smart idea, to say
the least.
 

Thank you gentlemen. Its proving to be a very complicated. I tried almost
everything I could. New library, calling BDE functions into java through
JNI, coming up with my own driver to connect and maintain indexes and few
other methods. Nothing seems to be working. Mapping the DLL works but as
kevin mentioned, under the higher stress level it fails.
Once again thank you TeamB members for the help.
Regards.
"Kevin Dean [TeamB]" < XXXX@XXXXX.COM >wrote in message

Please read <a href=www.hxtt.net/en/software/dbf/faq.html>9.
How to works simultaneously with BDE's DBASE and FOXFRO driver.<a>. I
guess that Knopfler can continue his project now. HXTT DBF document is
at www.hxtt.net/en/software/dbf/ . BTW, HXTT Paradox document
is at www.hxtt.net/en/software/paradox/ , but it's not
compatible with BDE's Paradox driver until now. HXTT Text document is
at www.hxtt.net/en/software/text/ , but it's not compatible
with BDE's ASCIIDRV until now.
Dai Wei
HXTT Ltd.

Kevin,
HXTT DBF can work normally with your old applications. You need to
rewrite old batch application in Java so that your old user interface
application can begin to see the compatible lock from batch
application. HXTT DBF supports batch insert. You can find HXTT DBF at
www.hxtt.net/en/software/dbf/ .
With best regards,
Dai Wei
"Kevin Dean [TeamB]" < XXXX@XXXXX.COM >wrote:

Have you considered exporting the data to another db, such as MySQL?
That's thinking outside of your manager's box.
Otherwise, an ODBC connection would work fairly well, if you don't have to
convert the code, but simply (:) emulate it's functionality in the new app.
regards,
Dar7yl
"Knopfler" < XXXX@XXXXX.COM >wrote in message

Knpofler,
Can you please keep us up to date on your progress?
I'm fascinated by the decision-making process and attitudes
of your company's management and want to know how things
turn out for you.
You might want to keep a print out of the key posts in this
thread. If something bad does happen, you have the public
feedback that the problem was insolvable. Even if it's only to
leave for the next guy charged with the task.
Thanks
Tom
"Knopfler" < XXXX@XXXXX.COM >wrote: