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Heng Xing Tian Tai Lab of Xi'an City (abbr, HXTT)

HXTT Paradox
Driver problem reading/sorting records
Juan
2011-05-15 20:21:02.0
Hi. I have a delicate problem trying to read records from a .db file.

A query to retrieve records sorted by date, has unexpected results (not sorted at all). For example:

SELECT * FROM movtos ORDER BY fechaMovto DESC;

Also (and you might remember this issue from a previous post), a query using:

SELECT * FROM movtos WHERE fechaMovto BETWEEN 'date1' AND 'date2';

results in an error:

SQLState: 60000
ErrorCode: 393216
Error: java.lang.ArrayIndexOutOfBoundsException: 1

The same query using another syntax works:

SELECT * FROM movtos WHERE fechaMovto>='date1' AND fechaMovto<='date2';

but then

SELECT COUNT(*) FROM movtos WHERE fechaMovto>='date1' AND fechaMovto<='date2';

also returns the same error.

One interesting thing is that there are no problems reading the same file using the same computer but with a different tool (for example MS-Access 2000, Paradox Data Editor, etc.)

We are using your driver with a system that is critical for our business so this behavior is unacceptable.

We appreciate your help and prompt reply.

Regards.

Juan
Re:Driver problem reading/sorting records
HXTT Support
2011-05-15 20:28:08.0
>A query to retrieve records sorted by date, has unexpected results (not sorted at all). For example:
>SELECT * FROM movtos ORDER BY fechaMovto DESC;
Try "reindex all on movtos". It should be resulted by your index file.

>One interesting thing is that there are no problems reading the same file using the same computer but with a different tool (for example MS-Access 2000, Paradox Data Editor, etc.)
Because other engine won't use your index to quicken those sql.
Re:Re:Driver problem reading/sorting records
HXTT Support
2011-05-15 20:52:51.0
Checked your sent sample with the latest version:
SELECT fechaMovto FROM movtos ORDER BY fechaMovto DESC;
SELECT * FROM movtos WHERE fechaMovto BETWEEN '2008-12-31' AND '2011-04-06';
SELECT COUNT(*) FROM movtos WHERE fechaMovto>='2008-12-31' AND fechaMovto<='2011-04-06';

It seems normal. If you meet issue, please let us know.
Re:Re:Driver problem reading/sorting records
HXTT Support
2011-05-15 20:54:11.0
BTW, please download the latest HXTT DBF and HXTT Paradox, which has been modified and maybe will support some XML feature soon.
Driver problem reading/sorting records
Juan
2011-05-16 06:43:12.0
> Dear Juan,
>
> > What could possible be the problem in your opinion?
> Passed test with SQuirrel SQL Client 3.2.1 too. Please check
> getDatabaseProductVersion should be HXTT Paradox Version 5.0 . You
> should check and remove old package from Extra Class Path of SQuirreql.

Not at the application layer. I get the same results querying the database from my Java application. As I mentioned before, these files work fine under some other Paradox tools (tools not using Java or the HXTT driver for that mather).

This is why I conclude that the issue is related to the JDBC driver when working with these specific files.

One more observation is that the are some other files besides MOVTOS.DB and MOVTOS.PX Their extensions are MB, XG0, XG1, ...XG9, XGA, XGB, ...XGF, XH0, XH1, XH2, ... (seems like HEX based series), YG0, YG1, ...YG9, YGA, YGB (another serie). Maybe they are indexes as well and the problem is with those files? Do you want a copy?

During my days programming with Dbase III+, Dbase IV, and Clipper, I remember it was possible to set the index. If I was able to build & use a separate index for my queries, maybe I would solve the problem. But the HXTT drivers do not allow to specify which index to use. Could you add this feature?

I am counting on you to identify where the issue is.

Regards
Re:Re:Re:Re:Re:Driver problem reading/sorting records
HXTT Support
2011-05-16 06:58:24.0
>As I mentioned before, these files work fine under some other Paradox tools
> (tools not using Java or the HXTT driver for that mather).
Because other tools won't utilize XG? index files to quicken query.

>Maybe they are indexes as well and the problem is with those files?
> Do you want a copy?
Yeah. It's the key. Because you haven't email me the other index files. With these files, your issue should be recur. A simple run once "reindex all on MOVTOS" can fix it.

> the HXTT drivers do not allow to specify which index to use. Could
> you add this feature?
HXTT can maintain automatically all index files. XG? index won't be maintained automatically by other Paradox applications.

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