Main   Products   Offshore Outsourcing   Customers   Partners   ContactUs  
JDBC Databases
  HXTT Access v5.2
  HXTT Cobol v2.1
  HXTT DBF v5.2
  Buy Now
  HXTT Excel v4.2
  HXTT Paradox v5.2
  HXTT Text(CSV) v5.2
  HXTT XML v1.2
Offshore Outsourcing
Oracle Data Import/Export
DB2 Data Import/Export
Sybase Data Import/Export
Free Resources
  Firewall Tunneling
  Search Indexing Robot
  Conditional Compilation
  Password Recovery for MS Access
  Password Recovery for Corel Paradox
  Checksum Tool for MD5
  Character Set Converter
  Pyramid - Poker of ZYH
Hongxin Technology & Trade Ltd. of Xiangtan City (abbr, HXTT)

inserting nulls not recognized by Visual FoxPro
Phil Ehrlich
2015-03-06 09:28:41.0

Our company purchased your DBF driver and we have been trying to use it in a web application (Oracle ADF/WebLogic 12c), and we have recently noticed some inconsistent behavior between records inserted from VFP and records inserted from HXTT.

Notably, when inserting records with null fields, using ISNULL() in a WHERE clause in VFP does not find the records inserted from HXTT. We believe we have traced the issue back to the CDX files. We have been able to recreate the issue with a single record. The "good" and the "bad" tables (DBF files) look identical in a hex editor, but the CDX files are different. I have these files and can send them if you need.

This is the insert statement we are running

INSERT INTO cmsmsg (cmsmsgid, timesent, timeread, empownid, emplockid, pono, empsendid, oprecvid, opsendid, clsendid, clrecvid, subject, body)
VALUES (?, ?, null, null, null, ?, null, ?, ?, ?, ?, ?, ?)

Then we run this SQL from Visual FoxPro:

SELECT * FROM cmsmsg WHERE ISNULL(emplockid)

And no records are returned. If we run the same insert statement from within Visual FoxPro then the query returns the record.

Please note that the emplockid column is being passed a literal null in the insert statement.

The emplockid column is type Character(4). It is marked index (Regular, ascending, Expression=emplockid) and NULL is checkmarked in the VFP table designer.

Please advise.

Thank You
Phil Ehrlich
Re:inserting nulls not recognized by Visual FoxPro
Phil Ehrlich
2015-03-09 04:54:11.0
After further investigation, it looks like the HXTT driver puts null into the DBF file correctly, but not into the CDX index tag(s), so some queries using index optimization return incorrect results.

Please advise.

Thank you
Phil Ehrlich
Re:Re:inserting nulls not recognized by Visual FoxPro
HXTT Support
2015-03-10 08:29:25.0
Supported. Please download the latest package.
Re:Re:Re:inserting nulls not recognized by Visual FoxPro
Phil Ehrlich
2015-03-17 09:19:32.0
Thank you, the latest package has fixed the issue.

Search Key   Search by Last 50 Questions


Address: 9 Station Rd., Xiangtan City, Hunan Province, P.R. China
Postcode: 411100
Phone: (86)731-58225727
Fax: (86)731-58225727
Copyright © 1999-2011 Hongxin Technology & Trade Ltd. | All Rights Reserved. | Privacy | Legal | Sitemap